How do you deal with the person your significant other is cheating on you with? Do you hate him or her? Would you call him or her a slut to their face? Would you try to physically hurt them?
But maybe, that’s not the best approach. If you took a step ack to think about it, there’s something the two of you need to learn from that cheating. Cheaters should never prosper, and this is what you should do.(Source)