You shouldn't remain with a cheating partner.
Dave is at home when his wife Cindy comes back from being out with friends and admits to him she just slept with someone else.
Dave wants to react to Cindy's admission.
Dave tells Cindy that she needs to pack her things and move out as soon as possible as their relationship is finished.
Dave tells Cindy that it's OK, and she just made a mistake, and he's sure she won't do it again.
Dave gains a bunch of self respect and feels stronger and more in control of his life.
Cindy is emboldened to cheat even more and stays with Dave just to exploit him for money.