How do you let husband understand his affairs should stop?

Tell him that you will divorce him, or simply tell him to stop. If this doesn't work, then you can pretend that you are having an affair.

ANSWER:

You don't need to remind your husband what he was doing is a big mistakes, it's also a sin and immoral. But if he still doing it and his not worry about it, that's the sign that your husband doesn't care about you. It's time for you to let him go and think about yourself now. You don't deserve this kind of life with your husband. Let it go so you can move on..God bless you!