I wouldn't do shit to the guy, cause sometimes, it isn't his fault. It's HERS. She cheated, not him. There's a great solution to it, that will make her drop to her knees and regret it for the rest of her days.
Thought this up just now.
Step 1.
Write down the date this happened, and make sure you put it into calendars and reminders so you can prep for it the next time it comes around.
Step 2.
Take some full page ads out in your local newspaper, and make a really big ad page revealing that this day, on this date, however long ago, your wife (state her FULL name, the HS she went to, the street she grew up on and a picture of her in her yearbook and a current one) had cheated on you with another man, and ruined your marriage, after you had done everything that the perfect husband could do.
Step 3.
Take it to the courts, and demand alimony payments from her, because she's at fault for the divorce (and you need some income to pay for those newspaper ads).
Step 4.
Get someone to doctor some photos of her in a bikini or something, and have them put long droopy boobs on her, with a VERY bushy pussy, make about a million copies, and pay some local kids to run around putting them up at places that you know she'd go to (supermarket, hair salon, local porn shop, church, colleges/high schools, library, etc)
Step 5.
Here's where step 1 comes in handy. Etch that date into your brain, and repeat all of the steps..
EVERY..
SINGLE..
YEAR...
I'm the Picasso of payback.