biiv, your gay guy sounds like he may have a problem of his own. I've had that happen; I tried to make a friend in my apartment building 30 years ago and she was very friendly, talkative, had fun ideas but then she suddenly didn't notice me or "remember" having talked to or done things with me, etc. I got a bad "feeling" about her because her behavior seemed so out of anything I could imagine being my fault and in a couple months, a real friend moved into our building and after a bit was raving about this wonderful new friend she had and it was this same woman. I told my actual friend to "be careful" my actual friend was much younger and didn't have any experience living on her own, away from her parents, etc. and I didn't have anything I could quite put my finger on to tell her why to be careful but it turned out the other woman was on drugs and suicidal and in the end, my actual friend got hurt.

As someone said earlier, always trust yourself. It's actually all you have to go on with other people. If you can't remember saying or doing something that was "wrong" then it's likely the other person has some trigger happening and you didn't say or do anything wrong, it was their take on it. But if you have a clear conscience, can't think of anything yourself, always give yourself the benefit of the doubt. You're the only one on your side and so you should always be 100% on your side :-)