Sherlock couldn't hide his smile. He was kneeling on Mycroft's bed, still half-dressed. He was too excited to properly undress. Mycroft, on the other hand, was deliciously nude and leaning against the pillows. In the warm light of the bedside lamp, Sherlock could see everything, Mycroft's chest, broad shoulders, freckled arms and his belly.
Mycroft's belly was Sherlock's biggest weakness. He couldn't rationally explain his fascination with it, nor could he get enough of it. There was something incredibly arousing about it, its softness and size drove Sherlock mad with desire. When it was hidden under a waistcoat, Sherlock would imagine unbuttoning it with his teeth.
The only problem was Mycroft's attitude. His insecurities made him question the nature of Sherlock's slight obsession with his tum. He would swat Sherlock's hand away from his belly. He would distract him with a blowjob. He would push Sherlock on the bed face-first to stop him from staring. The last one was effective only because Sherlock was too happy with Mycroft's bulk weighing him down to struggle and argue.
It was a challenge to outsmart Mycroft and Sherlock loved challenges. He discovered that Mycroft was far less defensive after a good orgasm. While he was basking in the afterglow, Sherlock would lean over his belly, officially to clean the mess he had made. Most often, Mycroft would let him do as he pleased without too much complaining. The other option was to have Mycroft on his back and suck him. Occasional mouthing of the area above his groin was then more acceptable.
The season of warming stews and hearty soups was difficult for Mycroft. So many temptations, so many calories. But the biggest threat to his diet was Christmas sandwiches. He was too weak to resists that temptation. Turkey, stuffing, smoked ham, bacon and lots of mayo. Mycroft didn't tolerate spinach leaves, as there was no place for healthy ingredients in his festive sarnies. He didn't mind cranberry sauce as long as it was tangy. He loved moist, indulgent sandwiches that somehow eased his Christmas-related stress.
The insane amount of bread and meat and mayonnaise resulted in a bigger belly. Sherlock could hardly control himself, he wanted to stroke it. Stroke it, squeeze it, kiss every inch of it. If only Mycroft let him take pictures... It'd be a disaster if someone saw them. How could Sherlock explain nude pics of his chubby brother?
Sherlock wrapped his hand around the base of Mycroft's cock to steady it and closed his lips around the head. He heard Mycroft's contented sigh even before he started sucking. He liked to take his time. Not only to test Mycroft's patience. Sherlock didn't want it to end too soon, he loved the heavy weight on his tongue and the ache in his jaw. Mycroft knew it and never refused him.
Sherlock relaxed his throat and slid down, filling his mouth completely. That wasn't the most comfortable feeling, but the thought of doing it for Mycroft made it worth repeating. He stayed down as long as he could, then pulled away. He knew Mycroft was watching him, staring at his half-open mouth and the tip of his tongue licking him. He swallowed him again, much slower this time to let Mycroft truly appreciate the view. He hollowed his cheeks and rubbed the underside of Mycroft's length with his tongue, humming softly.
Mycroft was lost in pleasurable sensations, his head was thrown back against the pillows and his hand was on the back of Sherlock's head. That was a perfect moment to touch his belly. He did lightly, just fingertips skimming across his stomach. Then he pressed them more firmly, almost kneading him like a cat. Mycroft either genuinely didn't notice it or chose to ignore it. Sherlock wanted more. He let Mycroft's cock slip out of his mouth. He placed a small kiss on the head, then on the side and nuzzled Mycroft's groin for a moment. Then he moved upward and stopped when he was leaning over Mycroft's middle. He dragged his tongue over the fleshiest part, then, on an impulse, pressed his lips to Mycroft's biggest fat roll and gave it a few sucks.
'I can't look away for a second, can I,' Mycroft muttered grumpily. He tried to push Sherlock away, yet only half-heartedly.
Sherlock grabbed Mycroft's hand and glanced at it. 'Maybe next time I'll tie you up.'
Mycroft chuckled and freed his hand with little effort.
'I have Lestrade's handcuffs,' Sherlock tried again.
Mycroft patted the top of his head, smiling. 'If you want me to use them on you, all you have to do is ask.'
Sherlock wanted to be angry, but Mycroft was right.
'Maybe I'll let him do that,' he said nonchalantly and dipped his tongue into Mycroft's navel. 'He has a dad tum, too.'
Mycroft narrowed his eyes. 'Is that so? Would you let your DI have his way with you? Even though he has filmed you on his phone every time you were half-conscious or drugged?'
'Maybe I would,' Sherlock replied stubbornly when Mycroft gripped his chin to stop him from licking him. 'Let go of me, I'll be good.'
When Sherlock returned to the spot between Mycroft's thighs, he saw his erection had softened noticeably. Jealousy didn't fuel Mycroft's desire and Sherlock had to put a lot of effort into making him hard again. Each swipe of his tongue and each squeeze of his hand made Mycroft a little less unhappy with him. Sherlock took him into his mouth again, this time keeping his hands to himself.
Soon he felt Mycroft's palms cupping his face, his thumbs stroked his cheeks. Sherlock wouldn't resist if Mycroft pulled his head down, but Mycroft never did that. Such a big softie. A wave of a warm feeling in his chest made Sherlock's rhythm falter. He didn't think he could do it to Lestrade, the idea of letting someone else than Mycroft see him so vulnerable was unappealing.
Mycroft was tensing up and gasping, his hold on Sherlock's face tighter than he realised. Sherlock didn't mind it and ignored Mycroft's warning. He loved the satisfaction of making Mycroft climax inside him. He swallowed every drop of his release without choking and wasn't in a hurry to move away. Mycroft was breathing heavily, still caressing his cheeks.
Sherlock eventually let him slip out of his mouth and sat up. Mycroft's round belly, so very grabbable, was begging to be touched and nipped. He was sure it would jiggle if slapped. Or...
He ran his tongue over his palate with a wince. 'Hmm, bitter,' he remarked, 'like you.'
Mycroft laughed. His belly did jiggle. Sherlock stared, fascinated.
'Oh, you prat.' Mycroft straightened his back and pulled Sherlock towards him. He quickly tugged Sherlock's trousers off to get to his cock. 'My turn.'