Fantasy
Xander kicked the covers down to his knees when the light in the hallway went out. His hand slipped down to the crinkled waistband of his boxers and paused there, fingers tracing tingling lines across the small stripe of exposed flesh between his ridden-up T-shirt and his boxers.
He cast about for a fantasy as he pushed his fingers under the elastic, finding the warm, already-hardening flesh of his cock.
Cordelia was the first thing to come to mind, of course. That was a habit he hadn't yet broken. He quickly shoved those thoughts aside. Too much badness there. Willow, of course, was similarly off-limits.
Which brought him to Buffy, naturally. A perennial favorite, even if she would kill him--probably literally--if she ever found out.
Xander grunted and felt his lip curl in something like a smile as he pressed his palm up his hardening shaft. Yeah, Buffy. But wasn't that part of her appeal, anyway? That whole kill-you-with-a-pinky charm? A full-colored image flashed through his mind of Buffy, full of that Slayer rage, flinging herself at a vamp. His cock twitched and he tugged at it, curling his toes at the rush of pleasure.
In his mind, fantasy Buffy turned and focused her razor Slayer eyes on him. He began to pump himself slowly, letting the fantasy uncoil lazily, letting her stalk towards him, reach out and touch him, a hazy presence in his mind before he took a moment to try and imagine her naked.
Normally, he got about as far as imagining breasts, with nipples, and maybe some pubic hair before that was it, he was done, and he'd roll over and get to sleep. Tonight, though, Buffy stood before him in his mind, naked, and he just... wasn't quite there yet.
Then a door slammed.
He froze, hand still on his cock, and waited. Footsteps stomped down the hall then down the stairs.
He relaxed again.
He tried to rekindle the fantasy, but his mind was still a bit unsettled and for some reason, the first thing that came to mind was... Giles. An annoyed, glaring Giles, who seemed to be incredibly pissed--even more so than Buffy--that Xander had dared let his image cross his mind at a moment like this.
Xander tightened his grip and began to move his hand again, slowly, all the while trying to will away the annoyed, tweed-clad librarian who was continuing to stand there in his fantasy and glare at him through those glasses that he had mercifully gotten rid of over the summer.
Okaaay, Giles, Xander thought, rubbing his thumb at the moisture at the tip of his cock and shuddering at the delightful tingles, Shoo. Go on, now. More naked Buffy, please.
His mental Giles, however, only sort of gave off an impression of smirking, and then, instead of naked Buffy... he had naked Giles. Well, mostly naked Giles, anyway. He didn't quite picture all the really naughty bits, but Giles... well, he had seen quite a bit of Giles, over the summer, after the torture, so this image was very clear to him. Giles had strong arms, one marred by that old tattoo, and a hairy chest, and a bit of middle-aged spread. He was a big guy, nothing like the teenagers Xander saw in the locker room. Big, and older, and, and... Xander's hand hadn't stopped. His chest was damp with sweat and he was pumping himself faster.
He was panting and rocking; desperate and close.
He'd touched Giles. Over the summer. A lot. He could remember, very clearly, the way Giles would shut his eyes as Xander helped rewrap the bandages around his chest, the way he would flinch when Xander's knuckles brushed his skin. But he'd let him, and he hadn't complained.
He remembered the unbelievably heavy warmth of him, staggering out of the mansion. The way he'd stumbled to his knees in the sunshine and gasped a wet sob, gripping Xander's shirt, his face pressed to the outside of Xander's thigh.
Xander had been hard, then, had blamed it on the adrenaline rush, but now, as he remembered it, his cock turned rock-hard in his hand, and dampened his fingers, and he was so, so close. The fire rising inside of him urged him on, and nothing could stop him now. He needed-- just needed. Would die if he stopped now.
Instead of fumbling to his feet, in his mind, Giles stayed on his knees, and Xander turned, turned just enough so that instead of his thigh, Giles' forehead was pressed into the crook of his hip, and then, then Giles lifted his head and opened his mouth--
Xander came with a choked-off cry.