Her: I just found the Peak District is not far from the city. Have you been there?

Yeah been there a few times, beautiful place. Maybe that can be our second date
 This message works well here as it shows a sense of cocky humor that you are already assuming there will be a second date before you’ve had the first. It uses callback humor because they have already talked about the first date to remind her that is an unfinished thread but also to seed the idea of a second date.