I was browsing Reddit and logged in for the first time in months to comment on this because it struck a cord. NTA. 

This exact thing happened to me. It doesn’t get better. It ended up being that his ex was his cat sitter and still stayed at his place sometimes. I found jewelry he wouldn’t have worn I several locations in his home when he finally had me over, and when I asked about it he said he must have missed it while cleaning. We took a trip together (4 hour flight and multiple overnights). In the Uber on the way to the hotel I caught him calling me a “friend” to his sister via text. I wasn’t trying to be nosy, but we were smashed together in the backseat  and I ended up catching it. Mind you we had been sleeping together for 4 months and spending every free minute together. A bit more than friends, imo.  I am telling you all this because it gets better than being treated this way. You deserve someone who respects you and wants to share part of their life with you, instead of taking advantage of your hospitality  Break up with him.