The habit started with Percy's old Camp Half Blood t-shirt.
Not that he noticed, at first - he'd seen her in that old orange t-shirt so many times that when he mentally undressed her (something that he'd never admit to her, but he does all the time) she was automatically wearing it. It didn't even register as not hers. Also, the first couple of times when she did it - padded into his bedroom early in the morning, wearing nothing but that orange t-shirt, Percy was too busy thinking legs legs legs legs hey, is there anything on under that? to really pay attention to where she'd gotten the shirt from.
In the winter she picks up Percy's old college sweatshirt.
When he walks into the kitchen one chilly morning he freezes in his tracks, merely watching as she puts coffee on to brew. At the moment he can't even remember the name of the institution - it was some place that was willing to let him attend before he could apply for the police academy - and yeah, it's printed across the front of the hoodie, but who in Hades is looking up that far? A lot of the time he thinks that Annabeth's legs are her best feature, and it's really such a shame that she usually chooses jeans or slacks because she can wear the hell out of short skirt. Or, in this case, a long hoodie.
When she reaches up into the cabinet the hoodie lifts, giving him a glimpse of the curve of her ass, and yeah, there's definitely nothing on underneath that sweatshirt. He was already semi-hard when he rolled out of bed, but now he's at full attention, and he must make some sort of noise, a choked off gasp, because she glances at him over her shoulder, through long blond bangs, and beams at him.
"Go back to bed," she orders him, nodding her head back towards the bedroom. "I'll bring us coffee."
He shakes his head mutely and shuffles forward, slipping a hand under the hem of the shirt and running it across the plane of her stomach. Annabeth squeals and squirms against him. "You're cold!" she complains, and he can't tell if she's trying to wriggle away from him or closer to him. "It's too cold to do this out here, you wouldn't believe the draft - OH."
She cuts herself off because he's dropped to his knees in front of her, hooking her knee over his shoulder and forcing her to brace herself against the kitchen counter.
His hands are cold, this he knows, but his breath is warm and her complaints soon melt away into moans.
In the summer she chooses to forgo wrapping his birthday present.
"...Is that a real Sanchez jersey?" he asks, cocking his head to one side, tapping a finger against his chin thoughtfully. "Or is it one of those ones you buy from a street corner that says NEL on the tag instead of NFL?"
Annabeth raises an eyebrow and looks down at herself, tracing the number 6 that raises over her breasts. "For how much I paid for it?" she asks. "It better be real. Or else I'm luring a monster back to a certain sporting goods store."
Percy laughs, and steps closer to her, allowing his eyes to sweep over her. The jersey is nice, sure - he's only been whining for it since before Christmas - but it's really Annabeth he's concerned with that the moment, Annabeth, with her long curls swept over one shoulder, with her hands on her hips, the dark red paint on her fingernails standing out against the green of the jersey. She looks about a million times better in it than Mark Sanchez ever could. He wants to tear it off of her and take her to bed, and judging by the darkening of Annabeth's eyes that's pretty much exactly what she's expecting him to do.
Instead, he gets a much more wicked idea. He scoops a toy football off his dresser - smaller than official issue, Nerf instead of pigskin, but it'll serve his purposes. "Here," Percy prompts. "Go long."
Annabeth rolls her eyes and takes a step back, holding her hands up in preparation and obediently catching the easy lob Percy gives her. She's laughing when she tucks it under one arm, but Percy ducks his head and charges. He wraps his arms around her, her yelp high pitched as his hands firmly grasp her ass, and hoists her up over his shoulder. Annabeth kicks, but only halfheartedly, and does not protest at all as he carries her off to bed.
He drops her unceremoniously into the sheets - already tangled, because despite Camp Half Blood's lessons being driven into his skull for years, he never makes his bed - and the shirt has ridden up, giving him a most glorious view of, well, pretty much everything. He unbuttons his jeans, and considers whether or not to pull the jersey off of her before deciding that it's more fun to fuck her when she's wearing it, and she must agree because when he throws himself over her she hooks her legs around his hips and pulls him closer.
When he enters her he looks down at her and grins. "Touchdown," he whispers, because he's a young male and even more than that, he's the kind of person who finds that exact kind of thing funny.
She grimaces, because she's his young girlfriend, and even more than that she's the kind of person who finds that exact kind of thing unamusing. Unamusing, but endearing, and quickly, she shuts him up with a smart shift of her hips, a small dig of her heels.
In the end, he thinks he might let her keep the jersey.
He's really glad Annabeth has done the last round of laundry.
This is the main thought he has when she surprises him from behind in their bedroom one evening, as she pokes a finger in his back and intones, "Freeze." When he turns around and sees that she's wearing nothing but one of his white button down work shirts, he's grateful because he knows its really clean; Annabeth has done the laundry and therefore it's actually free from coffee stains or a drunk's vomit or worse. She's grinning at him, one of her hands folded into a crude approximation of a gun, the other one holding up his badge, lifted from his jacket.
"I said freeze," she admonishes gently, tucking his badge into her breast pocket and laying the hand flat upon his chest, forcing him backwards until his knees bump the bed. Her lithe hands drop pretense and reach out, wrapping around the buckle to his belt and nearly pulling them flush. "Should I check to see if you're armed first?"
The mere implication is enough to get him hard, and she's not gentle as she undresses him, running her hands up and down his legs, across his chest, and, once she's satisfied he's no threat, through his hair as she cranes her head and captures his lips in a heated kiss.
Automatically, his arms wrap around her, dipping below to cup her ass and stroke up her back. Percy gets only a few seconds of the pleasure of her smooth skin before she stiffens in his arms and braces both hands against his chest. "Trying to take advantage of me in a vulnerable moment?" she demands, and pushes him back onto the bed.
As she crawls on top of him - still wearing his shirt, the gild from his badge glinting dully in the low light of the room - he asks in a strained voice, not nearly as outraged as the words might suggest, "Exactly who is trying to take advantage of who here?"
Annabeth laughs - laughs! - at him, and grinds her hips against his, and automatically he bucks up against her. He can already feel how hot and slick she is, and he wants nothing more than to slide his fingers against her, put his mouth on her, or flip her over and drive into her until she's screaming. Instead Percy pants a disbelieving laugh as she leans over him, and momentarily distracted from the pull of his shirt over her breasts, doesn't really notice that she's taken his wrists until she's wrapping his fingers around the bars of their headboard.
"Don't let go," she warns. "Or I'll get the handcuffs."
It's a very real threat, coming from her, and Percy swallows his moan, so hard it's almost painful. He's never admitted it to her on account of Annabeth is smug enough, but sometimes when she's giving orders - doesn't matter to who, himself or others - he has to stop and fidget uncomfortably until he gets control of himself again.
Then she reaches back, and takes hold of his erection - involuntarily, he thrusts into her hand - and carefully lines herself up, sinks down upon him so slowly he grits his teeth and arches his back and groans with impatience.
And oh, Percy has met cops like Annabeth, bad cops who get the tiniest bit of authority and let it go to their heads. Annabeth leans back from him, sighs in pleasure, and lets one hand trail down his stomach as the other one reaches for the buttons of her - his - shirt. She starts to unbutton it, gets to the third one that's been straining against her breasts, but as she's going for the fourth Percy stops her.
"No," he pants. "Leave it."
Annabeth's eyes narrow, and for a moment he thinks he's stepped over the line, but then she tilts her head and nods. "This is your only clean work shirt," she says warningly. "You'll have to wear it tomorrow."
"Wear it anyway," Percy insists, and his eyes roll back as Annabeth nods and starts to move.