There are two things Olivia never skimps on: shoes and underwear.

The former because there's nothing more embarrassing than losing a suspect during a foot chase to a turned ankle, and the latter because one never knows when one is going to need to strip down their skivvies and submerge themselves in a tank of saltwater.

It happens more often than she'd like to admit.

Like a good Boy Scout, she likes to be prepared.

She's pretty sure there isn't a chapter in the handbook on this.

'How the hell we're going to explain this to mall security if we get caught?' is front and center in her mind at the moment. She doesn't think flashing her FBI identification would work in their favor right now.

Okay, it's not entirely front and center. More like brief and fleeting. And then Peter does something with his mouth and her ear and that thought is completely gone.

It started like this: Peter let himself into her apartment, takeout coffee and bakery box in hand, just as Olivia was staring down the pile of cotton and Lycra on the floor in front of her lingerie drawer.

"Problems?" he'd asked as he put the box and the cups on the counter and came to lean against her bedroom doorjamb with his arms crossed like he was getting ready to talk Walter down from some harebrained scheme. She'd turned, at once taken aback at his familiarity in her home, and annoyed at herself for forgetting that this wasn't his first visit to her bedroom.

Actually, everything seemed to be annoying her this morning.

"I feel like the three bears," she'd snapped back. Then huffed and grabbed the offending pile of clothes.

"Somebody's been eating your oatmeal?" he answered, very careful, she noted, not to mention anything about sleeping or her bed.

"It's porridge, not oatmeal." Olivia stuffed the armload of straps, clasps, and ever-practical racing backs into their drawer and stalked past Peter, zeroing in on the waiting coffee. She might have let her arms brush his as she purposely strayed into his space, almost daring him to react.

She felt prickly, like somebody had waltzed into her apartment and shifted everything three inches to the left and she was still bumping her shins in the dark. And it wasn't that the other person had worn her clothes... her shoes... even her underwear. Hell, she'd done the exact same thing over there, after all. Intentional, or not. No big deal. She and Rachel used to share clothes all the time. This wasn't that weird.

No, it was that all the little differences she'd so carefully catalogued and analyzed (and that everybody else had missed) didn't bother her nearly as much as all the ways she'd realized that she and the other Olivia were exactly alike.

They even wore the same brand of underwear, for crying out loud. Really, what were the chances? Did Fruit of the Loom have that much of a market share across universes?

Peter was just an easy target for her frustration. For obvious reasons.

"You know," he'd offered, all cool and smooth. "We could always go shopping." He leaned back against her kitchen counter with a casualness she tried hard to ignore and sipped his coffee while he waited for her to turn over the suggestion and come up with excuses why they couldn't just play hooky today.

Frankly, she couldn't think of any. Walter had gotten to be more self-sufficient lately, and their caseload was quiet. Besides, skipping work is something she never did. Which made the idea all the more attractive.

Olivia grabbed a doughnut, one of the messy ones with the jam inside which she usually avoided because there was no way to eat them without looking like she'd tried to wear one. "Okay," she said after a few bites. "Let's go."

"Right now?" Peter quirked an eyebrow. If he was surprised at her complete lack of argument, or her suddenly absent sense of responsibility, that was the only clue.

She couldn't help herself. Maybe it was his Mr. Calm, Cool, and Collected act, maybe it was his refusal to play to her frustration that was annoying her, but whatever the cause, she could feel the tension building inside her, boiling and spitting, looking for an excuse to spill over and singe them both.

She licked the powdered doughnut sugar off her index finger, slowly, knowing full-well that he was watching her do it. Hoping for some sort of reaction from him.

All she got was, "Are you driving or am I?"

So that's how she ended up with her leg wrapped around his waist and her mouth buried against his neck in the Victoria's Secret fitting room on a Thursday morning.

Well, no, that part could be blamed entirely on the stuck bra clasp.

Mostly.

Sort of. In a roundabout way.

She's feeling kind of bold by the time she'd made a circuit of the store with an armload of lace and satin, and not a stitch of spandex in sight. Peter had dutifully followed her around, making suggestions and pointing things out with that patently bland expression of his, the one that says he's counting the cards played and waiting for the ace to fall, the other shoe to drop.

"How about this?" Olivia holds up a slinky little number that's more frills and plastic hanger than actual garment. There's no way she'd be caught dead in Walter's lab wearing it. (The risk of impromptu nudity is just way too high) The thing is, neither would the other Olivia.

And that's what makes it appealing.

Peter tilts his head, giving the excuse for a bra close consideration. "I don't know," he looks her straight in the eye. "I'd have to see you try it on." He doesn't even blink.

They're like kids playing at a dare and he's just upped the ante.

He's not the first boyfriend dragged along lingerie shopping, so Phyllis, the saleslady with the prim and proper silver perm doesn't say anything when Peter follows Olivia into the tiny cubicle and just pulls the floor-length curtain shut.

"If you need a different size dear, just shout." Her voice fades towards the front of the store.

Olivia doesn't bother answering. It's warm in here with the tiny halogen spotlights beating down from every angle and the heavy velvet curtain muffling the noise from the mall. Peter has staked his claim on the single chair in the corner, and he's sitting like some bored lord-of-the manor with his chin propped on his knuckles and a lap full of silk panties and lacey bras. Watching her.

Daring her to see the bet and raise him one.

She turns away from him, towards one of the mirrors and watches his reflection. She undoes the top button of her blouse and he shifts slightly, tilts his head for a better angle.

She takes her time with the second button, then the third, and when Peter moves again, she realizes that he's watching her reflection in the second mirror as well. He's got a full one hundred eighty degree show.

He realizes she's stopped undressing, and drags his heavy-lidded baby-blues up towards hers. It's at that moment that she knows, if they'd been at the poker table, now would have been the time to call his bluff. She undoes the final button and lets her blouse fall, watching him run his index finger along his bottom lip as he watches her.

The air is still in the tiny room and it feels like the temperature has gone up about ten degrees. She can smell his aftershave now and it makes her stomach dip. Peter holds up a mess of lace. "Try this one first."

Olivia reaches behind her back and undoes the first hook on her own ever-practical black bra. It's the second hook that sticks.

"Need help?" Peter drawls, always the gentleman.

She doesn't want to admit that she's losing the upper hand, so she just shrugs. Minor setback. Change of strategy. She's always been good at thinking on her feet. "If you'd like." It almost comes out sounding casual.

Apparently he does like. He takes advantage of the opening and lets the backs of his fingers brush along her spine as he works the clasp. He's not the only one who can take advantage of the mirror, she decides as she watches him. He leans in and she can feel his breath as it stirs the fine hairs on her neck.

Peter knows the effect he's having on her and takes a step closer until he's pressed against the bare skin of her back. He's warm, even through the fabric of his shirt, and she can feel him breathing, his heart pounding.

He lets his hand drop, clasp forgotten, lets his fingers slides down her spine until they rest lightly on her hip. She shivers, just a bit, but it's enough. His reflection smiles back at her, and then as she watches, he brings his lips down to the angle of her collarbone and dots her skin with light kisses.

Her breath catches as he makes his way up her neck and nips at her earlobe with his teeth. She leans back into him, lets her head rest against his shoulder and searches back through borrowed memories. Her alternate was bold, showy sometimes, and proud of the fact, but Olivia is certain that she's never done this.

It's enough.

A fire ignites, low in her gut, and she reaches up, behind her, and runs her fingers through Peter's hair. She catches a handful and turns, twisting into him so she can pull him closer. Captures his lips in hers. He gasps, surprised at the turn in play and takes a step closer, backing her into the angle of the corner. Her hands are not still either, roaming up under the hem of his shirt, sometimes slipping down to graze the skin just below his waistband.

Their breathing seems loud in the tight space. He dips his head so he can trail his lips down her neck to the V of her bra. She turns her head so she can watch him in the mirror, see him push aside the cotton and explore her breast with his tongue. She gasps and feels him chuckle low in his throat. She pulls his mouth back up to hers, arches into his body and finds he's hard against her.

As he presses his thigh between hers and pulls her knee up, trying for a better angle, she forgets why she was annoyed with him in the first place.

"Everything okay in there?" Phyllis the saleslady calls from the other side of the curtain.

Peter freezes with his hand halfway down the front of her pants and she bites into the fabric of his shirt to keep from gasping too loud. "You'd better answer her," Peter mumbles into the skin just below her jaw. "She might think she needs to come in and check."

Olivia swallows hard. "Fine," she manages, barely. "Almost done."

Phyllis seems satisfied. "Sure thing dear. Let me know if you need anything."

"Will do." Olivia's sure that comes out as a squeak.

"So what's next?" Peter breathes against her flushed skin. She can feel the suggestion in the way his lips curve against her neck.

"Well," she licks her lips and catches her breath. "I really could use a new pair of boots."

Peter pulls back a bit with a smirk. "Now that might be an interesting challenge."