River looked like she was thinking about his question long and hard. Maybe it was a difficult question, or maybe she was just being a smart ass. Both were viable options when it came to her. "There's no reason to anymore, but that doesn't mean I don't want to kill you. In a way it's almost personal now. Just because you were the only one to beat me, and that makes me a bit of a sore loser. But... do I want to continue to waste years of my life trying to hunt you down? Probably not. I'm not getting any younger." She smiled like she was hiding something, or at least making her own private joke.
Without being able to help herself, she reached out quick like a bunny and tapped his nose with her finger. Gently of course. She just wanted to see what he would do. "Well I need the TARDIS to get where we are going. Though it could easily be anyone's TARDIS. I'm not sure how much I actually need you. I think we're going to have to wait and see." That part bugged her a little, but not enough to show it. Gaining his trust was something she was pretty sure that she would never ever get, so why bother trying? Of course there were such things as a double bluff.