John didn't have a problem with nudity and since he and Sherlock had been having sex for a few months, he didn't even mind Sherlock's nudity.
What he did mind was looking up from making a blog entry to find Sherlock stood uncomfortably close to him, in nothing but his dressing gown—which was hanging open—and his rock hard prick nearly stuck in John's ear.
"Bloody hell!" John reared back. "What the—what is going on?"
"I need help, John," Sherlock said, without a trace of being perturbed by John's reaction.
"That much is clear, but I don't think it's the kind of help I'm qualified to provide!" John tried to stop looking at his cock and focus on his face, but it was right there. Waving at him. "In case you read in a book this is how you're supposed to ask for sex, the book was wrong."
"I have a very complex case I'm working on," Sherlock said, unmoving. "A woman says her husband was murdered by his mistress, during sex. I suspect there is no mistress and the wife killed him. There were copious amounts of semen on the bed, to make it look as though sex had occurred. However, I think it's too much for one orgasm. I think it was staged."
John couldn't wrap his mind around this. "How do you—stage…semen?"
"She might have been collecting it beforehand. There's no foreign DNA, it's all his. She claims her husband was interested in a kinky sex game in which climax is denied repeatedly and the result is an orgasm producing excess semen. She says he probably would have been doing this with his mistress as well."
John was still leaning back. "Fascinating. However, can we talk about this without your prick stuck in my face?"
Sherlock turned away. "I need to conduct an experiment," he said, sweeping over to the armchair. "I need you to bring me repeatedly to the brink of orgasm over the next six hours and then finally allow me release at the end." He snatched something up and turned to John, holding it out; a clear plastic measuring cup. "I'm going to collect it in this."
John just stared at him.
"You can do it however you like," Sherlock said. "You can use your hand, your mouth—we can even have intercourse. You can orgasm if you like. But you must stop when I tell you to, so I don't release."
"Why can't you just wank?"
"Dull." He put the cup down. "Besides, there's benefit for you as well."
Sherlock sprawled in the armchair, graceful and languid. He was still hard.
John, rankled, cleared his throat and turned back to his laptop. "Can I at least finish this blog entry?"
John tried to resume his concentration, but over the clicking of the keys he heard a faint, wet sound and looked up. Sherlock was wanking himself. With long, slow, languid strokes. John looked back at the screen and shifted in his seat.
A moment later, a soft groan drifted across the room. John curled his toes in his socks. He made several typos.
The wet sounds became more frantic. Sherlock was stroking himself harder, faster. John looked up and was transfixed.
"I'll do the first one myself," Sherlock said, voice breathy. "So you can finish your post."
John forgot what he was writing about. A few minutes later Sherlock abruptly stopped. He lay sprawled with his head on the back of the chair, legs akimbo, panting. The hollow of his neck glistened with sweat and his eyelashes fluttered as he gazed up at the ceiling. His cock was flushed and still very hard, bobbing against his belly in faint pulses.
"Give me fifteen minutes," Sherlock said. "Make sure I've calmed enough."
John wrapped up his post and closed down his laptop. By the time fifteen minutes were up he found he was rather eager to participate in the experiment.
John urged Sherlock over to the couch and they sat together, Sherlock draping his long, bare legs over John's lap and resting back on his elbows. John wrapped his fingers around Sherlock's prick—only half-hard now—and started stroking. In short time the organ swelled to a full erection again. Sherlock watched John's hand with darkened, drooping eyes.
"Was it difficult, stopping?" John asked as he stroked, slow and steady.
"A bit," Sherlock murmured. He shifted his hips, his arse pressing against the side of John's thigh. John could feel his muscles tensing, bunching.
"You're a stronger man than I if you make it to the end of this," John said. "Six hours?"
"I've endured worse."
They fell into silence as John stroked, careful, scared to go too fast and ruin the experiment. He smoothed the fluid leaking copiously from the head down the shaft, slicking it, making those wet sounds he'd heard before. Sherlock rocked his hips and gasped softly. John watched his face, turned on as well, quite hard in his trousers.
Sherlock moaned and dropped his head back, eyes closed, but he didn't say 'stop' yet. John could feel his legs tensing across his thighs.
Finally Sherlock lifted his head and gasped out, "Stop."
John took his hand off immediately. Sherlock was breathing hard, cheeks flushed, lips swollen and parted. He looked equal parts aroused and in agony.
"All right?" John asked him.
Sherlock nodded once. "I think…I might need a bit longer to calm down this time."
"We can watch some telly."
They did, sitting side by side on the couch, but not touching. Sherlock's prick gradually softened, though not all the way. John's did the same, staying just hard enough to remind him this was exciting. After about twenty minutes Sherlock turned to him.
"All right, let's go another round."
John licked his lips. "Do you mind if I go down on you?"
"Whatever you like, John. As long as you stop when I say."
John left the telly on and slid off the couch, between Sherlock's legs. His knees would probably make him regret it in the morning, but at the moment he didn't care. He leaned over, gripped Sherlock's semi-limp prick, and started licking it back to hardness. He tasted strongly of pre-cum, musky and tangy.
It didn't take long to get him back to a full erection. John then slid his mouth over him and started a slow, steady bobbing, trying to be as careful as he had been with his hand.
Sherlock threaded his fingers through John's hair and John couldn't help but go a bit faster with that encouraging weight on the back of his head. Sherlock was leaking more than usual. John could feel the salty thickness coating his tongue. Sherlock sighed softly above John and then gradually started moaning. His thighs tensed around John's head.
John nearly groaned when Sherlock said urgently, "Stop, John."
John slid his mouth off and caught his breath, working his jaw a bit. He wanted very much to taste Sherlock's release and felt his own spark of frustration.
Sherlock dropped his head on the back of the couch, chest heaving, and put his hands over his eyes. John could feel him trembling.
"You going to make it?" John asked.
"I have to," Sherlock's voice came out rough and breathy. His prick pulsed against his stomach. "This is torture. How does anyone find this erotic?"
John chuckled. "Well, it's pretty erotic from my end."
"It's just making me furious."
After a twenty minute break, Sherlock handed John a bottle of lube.
"Finger me this time. I want to find out if prostate stimulation affects semen production."
John had probably never heard a more un-sexy line. However, there was definitely something sexy about Sherlock stretched out on his side, John sitting between his legs, with two of John's slick fingers pushed up his hole.
Sherlock kept his hand wrapped loosely around the base of his cock, occasionally giving it a stroke, while John rubbed his prostate—not too hard, he didn't want to over stimulate him. Sherlock kept his eyes closed, breathing quick and shallow.
"I think I want to fuck you next time," John said. His cock was almost painfully hard in his trousers.
"As you like," Sherlock breathed out.
John used his free hand to cup Sherlock's balls. "Christ," he whispered. "I think you might have your answer already. You're so full."
Sherlock just moaned and gave himself a stroke.
"So hot," John murmured, still cupping him. "Hot and heavy and…full." His brain was too steeped in lust to pull out any more adjectives.
John felt Sherlock tightening around his fingers. "Oh God, stop," Sherlock choked out, very nearly a sob. "Fuck." He dropped his face against the couch.
John carefully withdrew his fingers and realized he was trembling. The room felt hot and his skin was prickling with need.
Sherlock didn't move from his position while he calmed. His breathing slowed, but his cock didn't soften much. Neither did John's.
John tried to focus on the telly, repeatedly adjusting himself, but neither helped. Sherlock took a bit longer this time to recover, nearly a half hour.
"All right," he finally said, and rolled onto his stomach. "You can take me if you like."
"Just let me get a condom."
John went and got one from his room, came back, and didn't even bother completely disrobing. He undid his trousers and pushed them and his pants down around his knees, and got behind Sherlock. After slipping the condom on, he found Sherlock still slick and loosened from the fingering and sunk right in.
John groaned at the tight heat enveloping his cock. He wanted to thrust hard, fuck Sherlock into the couch and have a glorious orgasm, but as before, he forced himself to take things slow and easy. He didn't reach under and grip Sherlock's prick like he usually did. Instead he grabbed his hips and started a careful, steady thrusting.
Sherlock groaned. "John. Oh…"
"Oh God," John gasped. "I don't know how you're managing this. I'm going mad just for my part."
Sherlock grunted against the couch cushion, hand underneath himself, but he didn't seem to be stroking, just gripping. "Don't hold back," he told John. "If you need to come."
John did need to come, but the stimulation wasn't quite enough. He started going a bit faster, plunging in deeper and harder. Finally the tight tunnel clenching around his cock felt just right, then Sherlock's body stiffened beneath him and Sherlock groaned urgently.
It took every ounce of will in John's body to still his hips. He gnashed his teeth in aggravation, reminded himself Sherlock was experiencing ten times the amount, and carefully withdrew while gripping the base of the condom.
Sherlock slumped, panting. "You can finish off if you like," he said.
John was tempted to slip the condom off, wank himself to completion, and come across Sherlock's back. Instead he peeled the condom off, but tossed it away and sat back.
"No, it's all right." John tried to catch his breath. "If you can suffer this much, I can go a few rounds without getting off too."
"Very noble of you."
The experiment continued, not only becoming more torturous, but somehow surreally, intensely erotic. John lost track of the time in between their bouts, each one taking less effort as Sherlock was becoming oversensitive, as well as nearly senseless. John started to feel like he was the one in charge of the experiment. He had to look after the test subject and make sure he stopped before the whole thing was ruined. Strangely, this made it even more intense, as did the fact John wasn't letting himself get off either.
After a few more blowjobs, hand jobs, and another round of fucking, John had Sherlock gathered in his lap. Sherlock's body was hot, his dressing gown soaked through with sweat, sagging against John limp and boneless as if he'd turned into water. John had his fingers buried deep inside him and he could feel him quivering like a live wire.
"Easy now, easy," John whispered against Sherlock's ear. His curls, pressed to John's cheek, were wet. "Almost there?"
Sherlock just nodded, making a strangled sound in his throat. He was open and slick from being fucked and fingered and John was in all the way to his hand. Sherlock was no longer touching his cock, arms around John's neck, hands gripping his shirt.
John felt the tell-tale contractions around his fingers and withdrew without Sherlock saying a word. Sherlock choked out a sob against his ear and John kissed his slick neck.
"Oh God," Sherlock gasped. "How long has it been?"
John looked up at the clock. "Four and a half hours."
Sherlock groaned, the sound vibrating against John's chest. "I can't go another hour and a half. I simply can't."
"Yes you can." John kneaded his arse. "Don't ruin the experiment now. You can do this. You have a great mind and you can defeat your need for the sake of results."
Such talk seemed to bolster Sherlock's determination. He sprawled back on the couch, catching his breath but seeming more in control of himself. John couldn't quit touching him. He stroked his calves and thighs, and then moved up, avoiding his cock, and smoothed a hand over his chest. He sucked at Sherlock's nipples and tasted the tang of his sweat. John felt like they were both covered in sex, absolutely wrapped up and drowning in it.
When Sherlock was ready again he asked John to fuck him.
"Don't use a condom this time," Sherlock said.
"Are—are you sure?" They hadn't talked about being exclusive, though John wasn't sleeping with anyone else and he was pretty sure Sherlock wasn't either.
"It's all right," Sherlock said. "I want you to come off this time, inside me."
"Are you sure you can last through that?"
"Just don't fuck me too hard."
Sherlock stayed on his back, legs pulled up, and John could watch his face. Sinking into his slick, tight heat without anything to dull the sensation, John was sure he wouldn't take long enough for Sherlock to get off in any case.
John tried to keep his pace slow and steady and not fuck him too hard, even though he wanted to put Sherlock's ankles back to his ears and ride the hell out of him. Just the fantasy was enough to push John perilously close to the edge.
"Oh fuck, Sherlock," John gasped. "God, this feels so good."
Sherlock reached up and smoothed a hand over John's cheek, then pushed it up into his hair. He gazed up at John with luminous, limpid eyes.
"Go ahead," Sherlock urged him. "It's all right."
John thrust into him a few more times, then he couldn't deny his body's responses any longer. He pushed up hard into Sherlock and started coming. Sherlock gasped at the sudden jolt and even in orgasmic bliss, John wondered frantically if he'd just spoiled the whole thing. However, Sherlock just tensed, screwed his eyes shut, and clutched John's arms. John pulsed inside him, paralyzed by the strength of his orgasm. If just the bit of denial he'd endured made him come so hard, Sherlock's head was going to explode.
After John pulled out, he couldn't help reaching down and slipping a finger into that soft, hot hole, overcome by the desire to feel his release inside Sherlock, marking him. Sherlock gasped, twisting his hips, but didn't tell him not to.
"Fuck," John whispered as he drew his finger out and it was quickly followed by a gush of his own semen. "You're overflowing with me. I put that in there."
"Oh, stop," Sherlock begged and tried to squirm away. "It's too much."
"I'm sorry. It's just—the first time…"
"I know." Sherlock clamped a hand over his eyes. "Please, don't touch me for a few minutes. I can't stand it."
John obeyed, though he really did want to touch him, feel him, hold him after such a thing. He went to the bathroom and cleaned up instead and left Sherlock to calm down. John hated cleaning Sherlock off his skin, too.
When he returned to the living room Sherlock was lying on his side. He lifted his head and looked with an unfocused gaze at the clock. "Forty-five minutes," he said. "One more time, then the time after that I'll come."
John sat back down beside him. "My hand this time?" he asked.
"You can resume what you were doing. I can handle it now."
John dipped his fingers back inside him. By now he'd overflowed even more, staining his dressing gown. John pushed in deep and found his prostate. He swore it felt swollen from overstimulation and he tried to be gentle.
Sherlock gasped, his toes curling against John's thigh. He gave himself a few strokes, his cock glistening, stiff, bright red.
"That felt very nice," Sherlock said in a trembling voice. "You coming inside me."
"We'll have to do it again when you're in less agony."
A minute more, two, then Sherlock choked out for John to stop. John withdrew his fingers, coated with his own release.
After a moment Sherlock sat up, and then got up on his knees. He seemed to have become completely senseless, as he felt around the couch, panting, groping, as if he were looking for something, then fell against the back of it.
"I need—I need…" He reached up and pushed his soaked hair out of his face, eyes rolling. "I need to figure out how—I have to make sure not a drop of this sample is lost."
"I'll help you," John said. "Tell me what to do."
Sherlock motioned frantically across the room, wobbling on his knees. "The cup."
"I'll get it."
John got up, fetched the measuring cup, and brought it back. Sherlock tried to take it, hand trembling, but John touched his wrist and stopped him.
"I'll take care of it. Just calm down a moment."
"You have to make sure not to lose any. I have to measure—"
"I know. Breathe."
Sherlock did, head bowed, taking deep breaths. His cock hadn't softened a bit, still jutting up from his lap, and he had to be positively aching. John was glad Sherlock was finally going to let this end.
After a minute Sherlock lifted his head, swallowed, and nodded. "I need to figure out the right position for this."
"Here." John got up on his knees as well, facing him. "Stay like you are, just lean forward a bit."
John reached beneath Sherlock and gripped his cock. Sherlock gasped softly, close to his ear. John looked down and made sure he had the cup around the head of his cock. John lifted his head and found he was looking right into Sherlock's eyes, only inches away, and smiled.
"Now I can see your face when you come," John said. "I can't wait."
"Make sure you do this correctly," Sherlock warned. "I didn't torture myself this long to lose the sample."
John chuckled. "Try to trust me. There's a reason I'm your assistant."
John started stroking him. He felt like steel wrapped in hot, wet silk. John rubbed his thumb under the head, rolling his foreskin to add a little stimulation. He didn't figure Sherlock needed much more, but he wanted to make sure this time he couldn't stop himself.
Sherlock's face was a mask of helpless pleasure, eyes half-lidded, mouth open, cheeks red. John continued stroking, harder, more vigorously, not holding back or being gentle this time.
"Come on," John encouraged him. "That's it. This time you can let it all go. You must be dying for it. Your balls must be so full they're ready to burst."
Sherlock apparently couldn't find words. He just made a desperate whining sound and jerked his hips.
"Careful," John told him. "I need to keep the cup there."
Sherlock fell still and remained that way, aside from the constant tremors passing through him.
John's hand was swift and moving easy, completely slick with pre-cum. Less than a minute later, he brought Sherlock finally, blessedly to his peak.
Sherlock made a sound somewhere between a scream and a desperate gurgle. John had never heard something like that come out of him before. His eyes rolled back in his head and his mouth fell open so wide John thought he would break his jaw. He gripped John's shoulder painfully hard. At least John didn't have to worry about Sherlock writhing around, as he completely stiffened. Sherlock's cock pulsed in John's hand and John made sure to catch each thick shot in the cup. He was shocked to actually feel weight added to the cup.
John thought Sherlock might pass out before he finished, but finally he slumped against him—collapsed really, panting and shaking. John kissed his sweat-soaked hair.
"God," John said, continuing to hold the cup under his still-jerking cock. "That was—wow."
As soon as he was sure he'd gotten every drop, John withdrew and let Sherlock sag onto the couch. He lay face-down, still shaking.
John held the cup aloft and stared at it in amazement. He supposed he should feel strange, holding a cup full of his lover's cum, but the damn thing was literally half full of white, gooey liquid and he couldn't stop boggling.
"Sherlock," he said. He lowered the cup and stroked his hand through Sherlock's hair.
Sherlock simply held up a shaking hand, backing him off. He needed a moment and John didn't blame him.
John put the cup on the coffee table and went to clean up for the second time. When he returned Sherlock rolled sluggishly onto his side. His cock was sagging and his eyes were still bleary, but he looked more in his head.
John picked up the cup and held it out. "Congratulations are in order, I think."
Sherlock lifted his head and gazed at the cup for a moment, then dropped his cheek back against the cushion.
"Well what do you know," he said. "He did have a mistress."
John chuckled. "So—what should I do with this?" he asked. "It seems almost profane to throw it away and even more profane to take pictures of it for posterity."
Sherlock waved a languid hand. "Doesn't matter. Flush it if you like. Drink it, if you prefer."
"Mix it with some bourbon."
"There's a bottle under the sink." Sherlock rolled onto his back, breath still labored, and looked down at his cock as if he really didn't expect it to be functional anymore.
"I really hope you're kidding," John said.
"I don't know how to kid." Sherlock rubbed his lower belly and sighed, sagging against the couch.
John stared at him a moment, then turned and walked to the kitchen.
I'll leave it up to the reader to decide if John is going to the kitchen to wash it down the sink or get the bourbon. ;D