What we thought was a cuckold kink just turned out to be cheating

In my friend group there is a couple that you can see a clear power difference. She normally bad mouths him along with just pushed him around, but every time he says that it’s ok and that they are happy. I don’t like putting myself to much in others life’s so I leave it after asking and recently she messaged me. It was a picture of her in lingerie asking if I ever wanted to meet up and that he knows about it as is ok. He liked feeling it when its behind his back and that our other fiends is also into it as well. I ask him and he backed her up so I agree she was super pretty and took care of her self. And she was the complete opposite of how she was pretty submissive and super giving either blowing me or rubbing it when we stopped. But after hooking up we also messed around here we hung out both of us feeling each other up. Slapping her ass when she walked by if we were alone as she rubbed me over my jeans. And the way we got was after hanging out we all slept over and finding the situation hot we fucked in the living room. He walked in on us and think he was into it I told him to sit and watch me fuck her right. But he just started crying before running out we tried to contact him, he didn’t answer and they did break up. But it was hot i would tell you we stopped seeing each other after that but I would be lying.