Spoilers/Timeline: None/Set in future.

A/N: This is what happens when you put tipsy fangirls in a hotel room together: we challenge each other to fic ideas outside of our comfort zone. Thanks to SSJL for said challenge, beta-ing, and content suggestions. Thanks also to for feedback on the beginning.

Disclaimer: Bones does not belong to me. Title found in the gorgeous Sara Bareilles song Between the Lines.

"I'm going to have to shower for three days when we get back to D.C." He threw the SUV into drive and sped away from the truck stop. "I mean, like it wasn't bad enough to be in the middle of nowhere Kentucky, but," he glanced around as if checking to see that no one was listening in on their conversation, "there were holes in the bathroom wall in there."

"Surely you know what they're used for, Booth." She laughed and rolled down the window allowing the warm air to drift in around them.

"Of course, I know what they're used for, Bones. I just don't understand how anyone could feel that sex like that is satisfying in any way."

"Anthropologically speaking, it makes sense. The biological imperative is strong and it's natural to try and find release when possible."

"It's just meaningless sex then. What's so hot about that?"

"I wouldn't say trying to further the species is exactly meaningless."

He ran his hand through his hair and glanced at her. "You know what I'm saying."

She looked at him a moment: the stern set of his jaw, the arched eyebrow as he concentrated on the road. "Yes, I know what you're saying... but it's still not true, Booth."

"Then explain to me how the hell getting a blowjob from a stranger," his hands tightened on the steering wheel, "in a grimy restroom can be hot and satisfying."

"It's not always practical for an individual to seek out someone with their interests just for the purpose of having sexual intercourse. It's like going to a bar with the intention of meeting someone for a 'one night stand'; you're both looking to achieve the release you desire. In this instance the arrangement maintains the anonymity, which can be very arousing, while allowing for sexual gratification."

He slammed on the brakes, not saying anything as he made a hard right onto the ramp for the roadside rest.

"Really? We just stopped a half hour ago."

"I... I just need a break, ok?" She nodded as he turned off the ignition and climbed out. "You waiting here?"

"No, I think I'll stretch my legs a bit."

"Ok." Their eyes met for a moment before he turned, calling over his shoulder. "Meet you back here."

She nodded even though his back was to her and started towards the women's room. A splash of cold water probably wouldn't be such a bad idea.

She pushed open the door and headed to the nearest stall. Why did she always push him on the subject of sex? She wasn't naive enough to not recognize what was going on between them - it was complicated and intimate and hot and dangerous - so why did she have to add to the fire every chance she got? Some little voice in her head shouted the answer, but she quieted it. It wasn't time yet. For now there was a partnership to be kept intact.

Through the wall she heard metal clang against the linoleum. Him and that ridiculous belt buckle; she'd bet it was the largest anyone outside of Texas wore. She sighed and leaned against the door, surprised at the cool air blowing across her arms. She turned biting her lip as she realized what she was observing: a hole leading to the men's room.

Meanwhile, through the hole, Booth stood, palms pressed hard against his eyes, trying desperately not to picture the woman on the other side of the wall. She drove him crazy. The most innocent mention of sex from her made his pants tighten, his heart race.

He rolled his shoulders and opened his eyes, glancing at the graffiti on the walls before settling on the hole in front of him. God, not again. He tried to push it from his mind until he heard the sigh. Her sigh. Oh god, yes. Again.

Yes, the conversation in the S.U.V. was torture; this thing that had been building between them for so long - for too long - almost threatening to overwhelm them.

He heard her boots clicking against the tile as she paced and could practically sense what she was thinking. She relied so heavily on logic, continually challenged him with it and while, at first it had annoyed him, now he couldn't help but be a little – all right, a lot - turned on by it.

Another sigh reverberated through the wall and he couldn't take it: knowing she was there, just waiting. He stroked himself and pressed forward against the wall.

Her mouth surrounded him almost immediately, boldly moving up and down his length. He groaned low in his throat and braced himself against the wall as her cheeks hollowed around him and she began setting a torturously light pace.

Her tongue soon began swirling around him, increasing the tension as she began to pick up speed, taking him in further each time she moved over him. He began thrusting through the hole, no longer caring how ridiculous it might be, only knowing he needed her to have all of him. To take all of him.

Her hand slid underneath her pants and she began stroking herself in rhythm with her tongue against his arousal; god, she - they - needed this release. She was moving frantically now, moans muffling against his cock as she tasted and teased. His eyes rolled back at the sensation and he bit the inside of his cheek to keep from calling out her name.

She stilled for a moment, tongue lazily trailing across him, before increasing the tempo one last time. The warmth of her mouth, the feel of her sighing around him, was too much. He came, collapsing against the wall as her own gasp of pleasure echoed through the hole.

He steadied his breath as her hand reached through and their fingers laced together. His thumb traced across her knuckles for several moments before the door of the restroom slammed shut and he let go quickly.

He left the stall, shaking his head at the trucker who was grinning at him knowingly, and moved towards the sink. He turned the water on as cold as possible and took another breath, muttering, "I still hate this state."