Unpopular opinion but I could (not guaranteed that I surely would) forgive getting cheated on, depending on the circumstances.
Obviously she'll be sleeping on the couch (if not on the carpet or the doghouse) for months, and she'd have to do the bulk of the job to win me back, and at the first misstep she's out on her butt. But I could be willing to try to forgive - of course I wouldn't ever forget, and if it happens again she'll be out on her butt before she can even blink.