“C'mon, Cas. Do I look like I scare easily?” Dean asked, his arms out to his sides. “Please! I wanna see it!”
Sam had already left to pick up some food, planning to bring it back to the motel room. He'd gotten sick of Dean arguing with Cas after Cas had finally admitted that his trueform wouldn't burn a human's eyes out, but instead was too terrifying to look at.
“No, you have never seen anything like this before,” Cas repeated for what seemed like the tenth time.
“Cas, I've seen shit that would freak out pretty much anybody, but I not only handled it, I killed it,” Dean said. “I want to see what you look like. You're not going to scare me. You're still going to be Cas to me. C'mon. Please!”
“No,” Cas said.
Dean huffed. “I've. Been. To. Hell,” he enunciated, as if the thought was scary enough to make Cas see he could handle Cas' trueform. “You can't scare me.”
Cas' lip twitched. It wasn't much, but Dean obviously considered it a victory because he grinned.
“You have been warned,” Cas said.
“Yup, I've been warned. Now show me,” Dean said.
Cas took a few steps back, then shivered a little as he allowed his trueform to come forward. Dean gasped, his eyes widening and tears forming in the corners as he stood frozen. His jeans darkened as he pissed himself, but Dean was too terrified to care about the tears streaming down his face or the piss streaming down his legs.
Cas pushed his trueform back, no longer allowing Dean to see it. Dean was shivering, and as Cas looked down at the large dark spot on Dean's pants, his vessel's cock hardened. Cas ignored it, too fascinated by the piss that was filling Dean's right shoe, the piss dripping off the cuff of Dean's right pant leg.
“I, um,” Dean whispered, then took off for the bathroom, slamming the door shut.
Dean was pretty much back to normal by the time Sam got back with the food. He'd showered and changed, and Cas sat with them while they ate, watching Dean. The vessel's cock was still hard, and it was starting to annoy Cas, so he forced it back to its flaccid state by controlling the vessel's blood flow.
Dean didn't mention Cas' trueform, and Cas didn't bring it up either, but he was intrigued by Dean's reaction to it.
Sam and Dean had taken care of the “ghost” that was terrorizing the Carter family when Cas showed up. Dean was packing the trunk while Sam was saying goodbye to the remaining family members.
“Hello, Dean,” Cas said, standing next to Dean at the back of the car, his trueform in full view.
“Cas, damn it, don't sneak up on-ah!” Dean yelped as he turned and saw Cas. His breath caught in his throat as he dropped a knife onto the ground.
Cas looked down at the crotch of Dean's pants, which was already darkening with piss. Cas pushed his trueform back after only a few seconds of allowing Dean to see it, but the damage had been done, and Dean was too stunned to stop himself.
Dean gasped, his body relearning how to breathe. “What the fuck?” he hissed, shakily bending over and grabbing the knife off the ground, dropping it into the trunk, then closing the trunk.
He walked around and got into the driver's seat, not saying another word. Cas got into the back seat as they waited for Sam. By the time Sam got into the passenger seat a few minutes later, Dean still hadn't said a word.
“Dude!” Sam said, his nose scrunched up as he looked down at Dean's wet crotch and leg. “Did that girl really freak you out or something?”
“Shut up, Sam,” Dean grumbled as he started the car and drove toward the motel.
“Ah!” Dean yelped, freezing in place as he walked into the bathroom.
Cas tilted his head, watching as Dean thoroughly wet his jeans. He'd timed it well, knowing Dean was heading into the bathroom to piss. This time he not only wet his jeans, but a puddle also formed around his right foot, soaking into the rug on the floor.
Dean only started breathing again when Cas shielded Dean from his trueform once more. Cas reached out, cupping Dean's crotch. Dean was shivering, but he didn't seem surprised by Cas touching him so intimately.
Dean wiped the tears from his face, then snorted. “If you liked it that much, you could've just asked me to piss myself.”
Cas felt Dean hardening in his jeans, so he unbuttoned them and pulled Dean's cock out. Dean groaned, still too shaky to do much as Cas started stroking him with his left hand. Cas unzipped and pulled the vessel's cock out, wrapping both hands around their cocks and stroking them together.
Dean leaned back against the door frame for support, his knees weak. “You like seein' me all wet, Cas?” he asked.
“Yes,” Cas said, leaning into Dean's space.
Dean grinned, his hips twitching as Cas jerked them off. “You wanna fuck me while I'm still all soaking wet? My jeans around my thighs?”
Cas gasped, stroking faster. “Yes,” he said.
“Or,” Dean drawled, “do you wanna fuck me on the bed while I'm all sprawled out on my back so you can watch me piss all over myself?”
Cas groaned, “Yes.”
“Or,” Dean drawled again, really getting a kick out of this, “do you wanna piss in my mouth as I suck your cock?”
“Yes!” Cas hissed as he came all over Dean's shirt, keeping eye contact with Dean the entire time and panting through his open lips.
Dean chuckled, his legs feeling a little stronger as he started to thrust up into Cas' hand. “Well, I guess that'll have to wait until next time since you've already blown your load,” he said with a grin.
Cas growled “No!” as he let go of their cocks, then wrapped his arms around Dean, lifting him and carrying him out of the bathroom, heading for the bed, Dean laughing the whole way.