41 [M4A] I saw my gf getting fucked right after we broke up

The shortened version of this story is that the one issue in an otherwise lovely relationship centered around my girlfriend’s friendship with brother of one of her exes. One day she leaves one of her chat accounts open on my computer, which I leave open, and later find messages from him expressing physical desire from my girlfriend, which she brushes off, but doesn’t explicitly reject, communicate to me, nor does she put up any new boundaries with this man.

Instead, when I’m away on a work trip, she goes out with friends, including him, and ends up out very late, with him (supposedly) crashing on her couch. None of the potentially contentious details of this are things the shares with me openly, but only after me asking pointed questions.

We have a fight, I accuse her of potentially cheating, and we break up.

I come home from my work trip early, and go to look at my girlfriend’s messages. Her messages with friends and with this guy do confirm that she did not physically cheat on me with him. But unfortunately, I find that she has told this friend about her break up, And that very day that I’ve gotten home from the work trip, has invited him over to do whatever he would like with her

I drive over to her place, not really knowing what I’m planning to do. But I know I want to know. She lives in a condo building, and I’m able to park and enter the building without drawing any attention to myself. At the door to her unit I can hear music, but can’t make out much else. The door to her unit enters onto a living room loft, so if they are in there, they’ll see me if I go in. The kitchen / bedroom are below in an open concept space. Once I work up the courage to open the door, I’m relieved that they are not in there. But a few careful steps forward from the door and I can see she’s naked, on her knees, sucking his cock.

It’s a brutal punch in the gut. Last time I saw her, just days before, were sweet. We were in love. But I don’t want to interrupt either, because she looks amazing. So I stay. There’s a den/storage room off the living room that she never goes in. I hide in there when they are done, imagining all the reasons why she might come into this room when he’s over. But she doesn’t. I can’t hear what they are saying most of the time.. But eventually the music stops and hear her start to moan again, so I come out and watch again. All evening I watch while they fuck, and hide when they’re done. Eventually at 2am I’m sure they’re asleep and I decide I shouldnt wait around to see if they fuck in the morning too.

When I read her messages with him days later, it confirms that he did fuck her again in the morning, because she tells him those were some of her favourite orgasms. I wish I’d been there to see them..

Message me if you'd like to chat with me about the relationship, what lead up to this, what I saw in person, or on her texts. It's all pretty hot and I love thinking about it..