That’s just wrong, and like the other answerer said, if he tries to make you feel like you’re being silly for worrying about it then you need to take that as a serious warning sign. I’m surprised he actually peruses these websites in front of you. You don’t think he’s trying to scare you off, do you? If not, either he just completely disregards your feelings, or I suppose it’s possible he really is just looking at these out of habit and has no intention of acting on any of them. But that’s a strange hobby, if he wants to be with you then he needs to get over it. Explain to him that it makes you feel bad when he continues to look at these websites when he has taken serious steps toward making a life with you at the same time. If he disregards your feelings, I would give that some very serious thought (and probably run), because I think that would be indicative of future problems with him. But find things you two can do together, like dance lessons, weekend trips, whatever — maybe he’s just bored. Best wishes!