I believe wife is attracted to another man in our group.

My wife and I went to a wedding over the weekend. I am at work right now and don't have someone to discuss this with and really need to get some advice on it. Basically my wife and I went to a wedding, everything was great as I held frame up until the end of the evening. I am not sure exactly where it went wrong or how. Either my wife had a little too much to drink and was just extra flirty, or she was sexually charged and very feminine. Going over it in my head makes me sick so I'm going with the more realistic answer that she was turned on by his presence. There was direct flirting, proximity. She leaned over to a seat across the aisle on the bus back and immediately this other guy, who does happen to be the AMOG, told her to sit down. How fast she sat her ass on the seat was astounding. In the moment I was embarrassed, but at the time I thought I may have been the only one to notice the signs. Not so much right now as I write it out. I feel like I fucked up allowing it to get that far, as in I should have been telling her to sit down. I was leaving my frame in those moments and now because I was obsessing over what was happening instead of focusing on correcting her behavior.

When we got back to the hotel, she was not following me. She was astutely aware of his presence and positioning herself in his proximity under the guise of doing something else. She wanted to go to the afterparty once we got to the room. We didn't go, the only way I knew how to get over it in that moment was to fuck my wife as hard as I could. It was pathetic. After I got off we were beginning to fall asleep, until she started sucking my dick again. We fucked again until she came then passed out. I've noticed in the past she is usually in a more aroused state after parties/events where this guy is there. It's worth noting I knew this guys wife before he did, so I cant ignore the possibility of a long term vendetta or equalling of the playing field type of behavior. It's subtle and it is fucking with me if that's the case. Having said that, I cant help but believe, that under similar circumstances where I and his wife were not around and the situation went a certain way, he would make a move, be able to handle her rebuttals to cheating, and she would want it anyway, then fuck him. She'd feel terrible after, but I'm not sure if shed ever tell me or if she's capable of hiding it. My wife has never given me reason to think this, except in these instances.

I tried to conceal my concern over this in case I was not seeing it correctly. On the bus i was mostly silent. It was all I could do to not mate guard. I cant see this clearly as it's a complicated social situation and I'm too invested. Am I overreacting, is this a bigger issue, am I missing a bigger picture?