He hesitates, not because she's approaching his boundaries, but because he's similarly trying to figure out where the boundaries are. As far as he's concerned, if he's succumbed, he's succumbed; sex won't make that much more true, especially when it's technically already happened. Besides, he's used to moving quickly, at least physically and in every other sense.

But if she has a concern... He draws back enough to look at her, trying to gauge where the mixed messages he thinks he's hearing are coming from. "If you're worried about Elizabeth coming back, you could take some things and we could go to my place..." he offers carefully. Is that subtle enough? Too subtle?