Permission to have affair?

[I tried hard]

Personally, I dont think affairs should be approved of. I think this is to relieve her of the guilt of it and she expects that you will be there waiting for her. Nothing to lose. I can understand why affairs happen but it's a choice to have one. If she is 80% sure sure she will come back than she should be 80% sure this is the wrong thing to do.
I think the first instinct may be the wrong one because its emotion based. I'm sure that someone here has had a similar sich and can give advice.

I'm jaded because of my wife is having an affair now even after trying hard for a year and I've given up.