I don't think she wants to "keep him" at least I hope not!
I think the problem is she's feeling guilty because she egged him on, and now wants to drop charges and is not sure what to do.
My take on the situation, ...yes, you egged him on, ...however, there comes a time in everyperson's life where they have to take responsibility for their actions. So you pissed him off bfd. It's not like you
made him kick your door in, or trash neighbourhood pubs. He did that of his own free will.
He's an idiot for cheating in the first place, 2
nd for leaving himself logged on to your computer, and 3
rd for behaving in a socially unacceptable & unlawful way.
You've made him an offer to grow up, bury the hatchet, pay for the damages and let bygones be bygones.
If he chooses not to accept it... press charges. Follow thru. Don't allow yourself to be intimidated.
You wanna drop charges so his wife won't find out?
wtf! There are consequences for innapropriate behaviour and if you refuse to stand up for yourself, then you deserve to be victimized.
Just my 2 cents
ps - Sounds like a possible domestic abuser in the making (if he's not one already).