Infidelity is the New Black

So here's the situation. One of my best friends is fucking one of my ex's. He's married with a 1 1/2 yr old boy. When I broke up with this girl, she started seeing him as a chiropractor, and I didn't mind. I really didn't care about her and didn't think anything was going on because he was married. But then I found out recently that they have been hooking up for the last 6 months. I really don't have feelings for her, though no one believes me. I even tried to hook my other friend up with her, but she refused. I have been in the situation where one of my friends is interested in my ex, same girl coincidentally.

The first time, the guy wasn't so much a friend by choice, but a friend because we hung out with the same people. He didn't say anything and neither did she. I was 22, she was 20 and I wanted to kick his ass, but I didn't. I kinda regret that. It was college, and I probably wouldn't have gotten into trouble for it, and damn it would have felt good to stick it to someone who tried to fuck me over like that.

The second time, was a really good friend of mine in college. He and my ex and I hung out all the time. I never suspected anything was going on because really, it wasn't. He had my back when my ex started fucking around. years later, when I was living in SF, he called me up and told me he was coming into the city and wanted to have a couple of beers. We had a good time, for the life of me I can't remember where we went. But on the ride home, he told me, and I had mad respect for him handling things the way he did.

This time around, I wanted out of the relationship so desperately. But my friend involved is not just some guy, he's been one of my best friends for the last 20 years. it really fucking hurt when I found about, because everyone suspected that he was hooking up with her, but I defended him fiercely. Then i found out that he lied to me and was fucking her behind my back fo 6 mos. He used me and lied to me and that hurt the most.

Question now is what do I do? how do I move forward? Do I let my vengeful side get the best of me? I want to rub it in his face because I know he is still seeing her, and I know he is lying to his wife about it. I also want to continue to be friends with him because I know how valuable having lifelong friends is. He's going to need the support of all of us when he finally realizes how badly he fucked up.

I think I can get evidence of the fact that he is still seeing her. but if I do, I don't think he would ever forgive me. As much pleasure as I would take for exposing him as a liar, I still have moral reservations about doing it. I could be the straw that breaks the camel of divorce's back. At the same time, if I refrain, aren't I just letting him take advantage of me doing the right thing like Reid did?

If I let it go, the truth will probably come out anyways, this is Hawaii, shit like that don't stay secret for long. so I guess the best thing to do is to shut the fuck up, and don't tell anyone that i'm not going to do anything. Because then, he will feel smart for being able to take advantage of other people doing the right thing like he did before. OMG, I can't even believe that I'm dealing with this shit. People in Hawaii have no fucking integrity, no honestly and don't even try to do the right thing. I'm so fucking sick of it here.