I'm gonna do it. I'm just gonna fucking do it.

He wants to kiss Him. He wants to just lean over and fucking kiss Him. They are on their way to Hogwarts, in the Marauders' compartment and Remus is with the Prefects and Peter is fast asleep, and he has been with Him all summer and it hasn't gone away. Sirius just wants to kiss Him.

He is talking, smiling and laughing at Sirius like He always does, and he's got a fake grin plastered across his face nodding absently while desperately trying to shoo away the thoughts of just leaning across the seat and putting his lips on His lips. He shouldn't want it. What if He didn't want it? Even worse, what if He did?

Sirius knows He is infatuated with Lily Evans, and Merlin, Sirius has plenty of girls lined up wanting his attention, but he wants to kiss Him, damn it. And he's going to do it.

Then, right then in the middle of the fucking compartment with Peter sitting three feet away, mouth open and snoring, Sirius interrupts Him mid-sentence and straddles His lap. Lips instantly find lips and He's surprised but doesn't push him away. In fact, after a moment of tense beginnings in which he is nervous He will shout or punch or hex, He starts kissing, too. Sirius can feel His tongue cautiously and carefully tease its way into his mouth, and it's ecstasy. Everything he thought it would be like. After the entire summer staring at those perfect lips and knowing that he can't have them . . . this is what he was missing out on.

The kiss becomes hotter and wetter as tongues begin dancing across each other and hands begin tentatively exploring hard bodies. He is lean and lithe from years of Quidditch, and he is compact and muscular and gorgeous from the Adonis genes of the Noble House of Black. And He is dragging clipped fingernails down his tense, muscled arms, and he feels himself beginning to harden.

While Sirius is straddling His lap, He drags those strong hands down to his arse and grabs roughly, and he can't help it but he thrusts his hips forward into His hips, and a sound fills the air.

"Shh," James whispers, silent as a breath. "Peter."

The sound of His voice changes the moment, and it suddenly becomes real. Not that Sirius wants to stop it, but all of a sudden, it's real and he's really kissing James Potter. Snogging James Potter in the Marauders' compartment on the Hogwarts Express while Remus is with the Prefects and Peter is fast asleep. And James isn't angry or shouting or punching or hexing; He is telling Sirius to be quiet or else the moment of delicious snogging will end abruptly when Peter wakes.

And Sirius wants Him even more.

So, in silence, he crashes his mouth onto His and pushes his hips forward dangerously, and he can practically feel His pulse through their trousers. Then, suddenly, there are hands jerking at shirt tails and He has pulled up his shirt and is working on his buttons. Sirius suddenly realizes that He wants this, too, and that even though it's a little bit wrong (possibly a lot bit, but he'll worry about that later), it's going to happen, the way he's been imagining it's going to happen for one or two or six years. And there are hot, calloused hands on his taut, rippling abdomen and the sound of a zipper and a button, and then that hot, calloused hand is on something else and Merlin, he's going to come right now.

He doesn't, and he thanks every deity that might exist that he's been saved that embarrassment, but His hand is still there and it's gripping and teasing and pulling, and their breath is loud and hot and heavy, and how is Peter still sleeping through this?

Sirius takes His lip between his teeth and nibbles, and he runs his hands through His messy hair the same color as his own, and his hips are thrusting of their own accord now. One of His hands is pumping steadily and the other has a rock hard grip on his arse, and he can almost imagine His cock where His other hand is even though he's never thought about doing that before. And the thought of His cock in his arse sends him over the edge, and he spills all over His hand and shirt.

Is there enough time for more? Sirius thinks there probably isn't, but he's going to do it anyway because when will he get this chance again? The answer could be never, so he fumbles a bit sinking down to the floor between His legs, but succeeds and in a moment has His pants undone and His cock poised in front of his mouth.

The sound He makes when he puts that hard cock in his mouth is enough to get Sirius hard again. He thinks he ought to whisper, "Shh", like James did a moment before, but he really wants to hear that sound again whether Peter wakes up or not. He takes His cock deep into his throat and cups His balls with his hand and the sound happens again. James's thighs are tensing, His muscles quivering and He is close to orgasm, Sirius is sure of it. He sucks harder and He lets out that fucking incredible sound once more before he tastes Him in his mouth.

Merlin.

He is breathing hard, and so is He. Sirius gets out his wand and casts a quick, quiet cleaning spell while He is still relaxing, breathing hard and eyes closed. He climbs back onto the bench, next to Him but not on Him now. And Sirius glances over to Peter, whose eyes are wide open and his jaw practically on the floor, but when Peter notices Sirius is looking, he shuts his eyes and pretends to be asleep again.

And Sirius nuzzles his nose into His neck once, planting a hot, sucking kiss that might leave a mark, and then backs away. It smells like sex in the compartment, and Remus returns from the Prefects and Peter wakes up and wonders how long he's been asleep and how close they are to Hogwarts by now. He shrugs, and so does He.