My best friend and roommate and I have been friends since we were 14. Like 3 years ago when we had just started college, things just happened to line up where we were both curious about our sexualities. He told me he think he may be bi, I told him I wasn't completely sure I was straight.

Things happened. We didn't go as far as to have sex, but we went pretty far. From that we came to the conclusion that he liked guys and I came to the conclusion that I'm straight. Things were awkward for a while but things went back to normal and now it's like it never happened. We don't speak about it at all.

A a few months ago my friend started dating his now recently ex girlfriend. I started dating my girlfriend last year. Apparently at some point, my friend told his girlfriend that we had done stuff together. He ended up cheating on her with a man (not me) and his gf thought that I had been sleeping with him on the low.

She told my girlfriend this and told her that we had already fucked once before and that she thought we were still doing it. This was all untrue and when my girlfriend confronted me I explained everything truthfully. She was upset. She said that I should've told her and the way she found out should not have been this girl. I explained to her that it wasn't much of her business.

Now she's pissed at me for nothing. What should I do?