I'm going to get absolutely fucking downvoted for this, but I cheated once. I was in an extraordinarily bad place mentally (I was almost institutionalised shortly after) and the whole thing hurt me just as much as it did everyone else involved. I was incredibly fortunate to be given forgiveness, and the support I needed to heal, and I have never even thought of doing it again. Cheating is a bad thing, but not everyone who cheats is inherently a "bad person". Life isn't black and white like that.

So to answer OP, I would consider forgiveness only if there were circumstances which may have contributed, and on the premise that it absolutely would not happen again.