Supernatural, PG-13, Dean Winchester (with an unwanted guest appearance by Sammy Winchester). Going through puberty while sharing a motel room with your brother sucks.
Warning: Underage Dean is 14.
When Dean wakes up he has to piss, but he's hard as a rock, as usual, and he's learned in the past few months that the only way to relieve the situation is to jerk off. Usually, he'd take care of himself under the covers, fast and quiet, but Sammy is awake already, sitting cross-legged on the bed, watching cartoons.
He grabs the bottle of lotion he's learned to keep by the bed and shuffles, hunched-over, to the bathroom. Double-checks that the door is locked, and decides against the ice-cold toilet seat. He leans back against the sink, closes his eyes, and thinks of Tia Carrere.
He's just three strokes in when there's a knock on the door. "Are you done yet?"
"No, Sammy!" His voice cracks with the effort of not actually shouting.
"Cuz I have to pee!"
So do I, and I can't until I finish jerking off, so leave me alone!
"Just a couple minutes!" he shouts instead.
"But I have to peeeeee!"
He considers telling Sammy to use the kitchen sink, but that would be gross. "Be out soon!"
"Okay," Sammy mumbles through the door, but Dean can still see the reflection of Sammy's feet in the linoleum, he's standing outside the door, and Dean can't just jerk off with his little brother right there.
"Go away!" He's reduced to begging, now.
"Why are you being such a jerk all of a sudden?"
"You'll understand in about four years, now please please leave me alone."
He loves his little brother, really he does, but in the long moment before Sam retreats, he wants to strangle him a little bit, too.
Finally, he's alone with himself and it never takes long. Less than a minute later, he's cleaning himself up with a handful of cheap motel toilet paper, and then he's finally able to take a whiz and surrender the bathroom to Sammy, who glares at him as he hustles past.
He flops face-down on the bed, and notices as he does the telltale tingle in his groin.
Puberty, he thinks, is not for sissies.