When in a relationship, someone cheats on the other person, it is very hard to recover. There is a lot of trust issues that bubble up, every single move from then on out is going to be questioned, and when your partner says they’ll forgive you they more than likely don’t, at least never fully. It is a tough thing to forget, and an even harder one to forgive.
Sometimes it does work out and some couples actually make it out ten times stronger than before. However, sometimes it is just not worth it. The doubt never disappears and the two people involved will more than likely never be at peace, but instead someone always on their toes, waiting for it to happen again.