What a horrible situation to be in.
It wasn't a drunken shag.
it was a failed drunken shag
followed by an unprotected half drunken shag
Followed by a sober morning sexual encounter
No excuse. He knew what he was doing. And he's probably only owned up because he knew that shit was going to hit the fan at some point.
FWIW OP, I would want to know. The humiliation of multiple wedding guests knowing. The bride to be should have the choice before she marries him of whether to do so or not.
I would have given the groom to be the option of coming clean or an anonymous note being sent.
The outcome is the best you could have hoped for. You didn't need to step in, thankfully.
Years and years ago, I went to an event and a close friend's fiancé was there with someone else. He was drunk but not drunk enough to hide his horror when he saw me. Didn't deter him though - I saw him leave with her. And two of his mates were there too.
I was like you - torn on what to do. I went to my friend 2 days later and told her I thought I'd seen her fiance with someone. She called me a liar and never spoke to me again. It caused huge issues in our friends group. I found out years later that he'd set me up in the days before I plucked up courage to tell her. He planted seeds that I didn't like him and was trying to split them up and did she think I maybe had feelings for him. Looking back - she wasn't really ever my friend if she chose to believe I was the sort of person he painted me as.
They split up after he cheated on her (again).
I vowed I'd never get involved again. But I did. I worked with one of my best friend's DP. I found out he was sleeping with a colleague. I told my friend. She had the opposite reaction. The thanked me and said she was grateful as she couldn't begin to. Imagine how hard it must have been to tell her. She ended it. Now happily married with a lovely happy family. We've been friends for over 25 yrs
I'd do it again. Life's too short. People choose to stay. People choose to end it. They should at least they have that choice.
I hope they sort it out and get the outcome they both want.