My (38F) live in BF(35M) of 1.5 years slept with his ex girlfriend hours after we got in a bad fight.

Anonymous account for obvious reasons. After a night of drinking my SO and I got in a fight. I did not feel like staying and being yelled at (he can be quite bombastic) so I went and stayed with a mutual friend of ours who happens to be male. Our relationship is strictly platonic and he has been a confidant to both my BF and myself. In the morning my BF messaged me looking for the car. There was no concern for my well being or location. He said that he was packing his things and for me to bring the car back. I came home and he left. He said horrible things to me via messenger. He said that he had been bullshitting me the whole time we were together. I blocked him on all social media. Fast forward 2 weeks later...I unblocked him on FB. The next day he msgd me and asked me to go to a concert with him. I was not sure so, I asked if we could meet beforehand so that I could feel it out. During our meal I jokingly asked i f he had slept with anyone during our time apart. He said that he had slept with one person but that he felt horrible about it and that he really want to try to make it work. I let him know that I had not slept with anyone. He said that he just got really drunk and lost control. OK. We were on a break. So I felt like I could not really be that mad about it. We decided to try and give the relationship another shot. I agreed to go to the show out of town. At the set break he confessed to me that the person that he slept with was his EX-GF. I immediately left the show alone and went back to the hotel. I immediately called his EX. I have known her nearly 18 years as she works at a bar that I have frequented since I was 21. She apologized, said that it was not intended. They just got really drunk and were dancing and it just happened. OK whatever. She said that she is not trying to get back with him. We actually had a good conversation. So, I try to see if I can be ok with it. I cannot believe that he had the audacity to try and get back with me after sleeping with her, a supposed friend/peer of mine. Every time I close my eyes to sleep I see them together. I envision them kissing, touching, interlacing fingers, laughing and tenderness. It makes me physically ill. The more I think about it I get more and more angry. I plan on breaking up with him calmly this evening. He keeps saying that he is sorry and that he was not trying to triangulate us with each other. My question is, DID HE CHEAT? ALSO, How do I express the anger I feel in a way that doesn't make me look crazy but gets the point across that I hate them both. I am livid.

TL;DR My (38F) Boyfriend (35M) slept with his EX GF (she is someone I have known for many years) mere hours after we broke up. Two weeks after breaking up we reunited. One week into us giving it a second chance he told me he slept with her at a concert. DID HE CHEAT? How do I express the anger and ire I have for both of them without looking crazy? I am calmly breaking up with him this evening. I want to let her know that what she did was a huge betrayal and not how you treat a friend. I do not think that getting drunk is a very good excuse.

Submitted November 14, 2019 at 11:57AM by anonymousgrade https://ift.tt/2qRQbLO