This was something Booth had thought about before, even if he had never admitted it to anyone else, much less her. It only existed because of the close relationship they already had, being partners, spending each working day with each other. It had grown to be more than that, but everything had a starting point. Not that his mind could comprehend such deep concepts at the moment, he could only think of what was going on between the two of them, how she felt and tasted, what the next move would be. There might be consequences, repercussions, but they could face those when they happened. Right now it was about the moment that they were experiencing.
A low noise came from the back of his throat when he felt her tugging on his bottom lip, and then her warm hands were sliding over his hips. The action was almost teasing, but in all the right ways, were it only enhanced what he was already feeling. He could feel the waistband slide down, not much, enough that there was more skin on skin contact. His head tilted to the side and he moaned into her mouth, feeling her pressing into him. All the teasing she had done earlier, added with kissing her, feeling her body, did have him more than ready for her right then.
He broke the kiss and allowed himself a small breath, though he was starting to match her movements, rocking his hips against hers' hard. She wasn't fragile, and he knew she didn't want to be treated like that, though that didn't mean he'd be overly rough with her either. His lips found her neck, kissing and sucking on the soft skin there.