This is a bit ambiguous. Did you discover that he's bisexual and happily married to you, which wouldn't be a problem? Or that he's gay and cheating or not on you? That'd be horrible and I'm sorry if that's the case.

He's in love with himself???

So does that mean you both are cheating on each other with the same person! Please change your relationship status to "complicated"

Just look at it this way, that's one more thing you have in common.

My powers of precognition foresee either a three-way, a divorce, or both in your future... That'll be 80$.

Ughh

You **** him Mon, Wed, Fri. He **** him Tue, Thu, Sat. Everyone goes to church on Sunday. Problem solved. I shall move on.

Guess you can share!

Is he deeply narcissistic or are you in a situation where he's your attractive slutty best friend?

This is very vague. If he is gay then i'm sorry. I wouldn't hate him for it but it does suck and I can't know how much. Is he bi? If you found out from him cheating on you, I just hope you realize it's not because he's bi, straight and gay people cheat too. And of course is that is the case i'm sorry. There are many happily monogamous bisexuals, myself included. Was it finding some **** or him telling you? In which case, it may be a shock but it isn't anything bad. If he told you then i'd actually say that's awesome that he feels comfortable enough in both you and himself to tell you, though maybe sucky that it took so long. No one should have to hide who they are. As it's so vague I don't have a clue how to respond...

Gotta be honest I took it to mean that they were cheating on each other with the same guy.