My friend had sex with my wife and I think she enjoyed it.

Im(28M) in a bit of crisis.My wife(27F) and I know this guy since my university years. We shared everything together. College, house flat, flatmates. Through all these years, he is like a brother to me. He is an amazing guy. I know that he had a big crush on my wife for a long while. He tried to hide it but he wasn't discrete. He was never really making any moves though. I know that my wife wasn't particularly into him, but more into the idea of having an affair with him. She is the type of girl who likes to flirt heavily and be the center of attention. She is very attractive, so she was always being hit on.<br><br>&#x200B;<br><br>We invited him over one day and we started drinking. I went to sleep earlier while they went on drinking. I woke up in the middle of night to find my wife and my friend having sex. I didn't say anything and I went to another room to sleep. They thought that I didn't know because the next day we acted like everything is normal. But I know that they had sex. It was a one time mistake and not a planned thing, right? It didn't happen since, right? It was just a stupid mistake, right? Before I caught them, they were in the heat of the moment and they weren't thinking. Maybe he was too drunk to stop and my wife was also too drunk to stop it. Maybe she was scared or frozen. It wasn't until the next day that they realized what they have done. They both felt bad and they agreed to pretend that nothing happened. But why did my wife sounded like she was enjoying it? Why did she moan so loudly when he was inside her? Why was she calling his name? Why wasn't she scared? Why wasn't she frozen? She is the type of girl who likes to talk regularly during sex. I don't know if she does it to make me feel good or to turn me on, but she always says things like 'you are so big' 'you are so hard' etc. I heard her saying these and other things to my friend. I heard them having so much fun. I heard him asking her if she liked having a big **** inside her. I heard her saying how amazing it feels and how big he is. But she only says these things to turn me on, right?<br><br>&#x200B;<br><br>I know that they didn't plan it. They didn't do it behind my back for months, right? They didn't have an emotional affair, right? But still, I feel horrible. I feel betrayed. I feel that my brother and my wife did the most horrible thing to me. They weren't in the heat of the moment. They had sex many times and they both enjoyed it. My wife even had an orgasm. They didn't even care that I was sleeping in the next room. I feel so humiliated and betrayed. I don't know what to do.