In the whole of my dating life, which to date spanned 25+ years, I’ve never had a single guy ‘own up’ to just not being that into me. I’m not everyone's cup of tea either. I’ve got non-traditional ideas about marriage and motherhood, came from an extremely abused childhood and poverty, and am very passionate about my rights and opinions. Most of the time, they would flounder or make up some bs, but never once did I have a guy say to me, “I just don’t think we’re a good fit.” Instead, they’d go about dating me — through the course of which, they’d treat me worse and worse until I stopped dating them. I was always “the bad guy” in that I was forced to dump them. To date, I’ve also never been broken up with. I’ve always been the one to end the relationship.
Point is, if you don’t think someone is a good fit, don’t increasingly treat them like crap and make them feel like they’ve done something wrong. Instead, be the nice guy, stop wasting their time, and just say “I’m just not that into you.” No one likes to be rejected, but it’ll go over way better than using her for a few months.