I’ll make this quick, me and my friend are both in the military, he’s about to go to afghan, he’s not even 21 yet. He’s about to get married. Call me an optimst but of all those facts the one I’m worried about is the fact that he’s about to get married. To a girl I honestly think I could fuck if we were both drunk enough. Dude won’t listen, gimmie a course of action that doesn’t involve me shooting him in the face plz. Ty in advance.
Get drunk enough and fuck her. Throw yourself on the grenade. It’ll destroy your friendship, but it’ll save him from ruining his life more than he already has.
If you think she cheats that easily, you could always hire a private investigator to get some video evidence. Confront him with your own little homemade episode of “Cheaters.”
Really, there’s no way to do this without being tacky and creepy, so if you’re gonna do it, you gotta commit.
Otherwise, all you can do is refuse to be his best man.