Being cheated on is one of the hardest things to forgive, if it is even possible. In my mind it breaks a very foundational trust that cannot be overlooked in a relationship because without trust in the person you're with everything, and I mean everything else falls apart. If they are willing to lie and cheat on you at this very important and critical level, all other lying and cheating, deception is possible which undermines anything they say to you or do with you... etc. So it is quite a difficult thing in my mind to get past.

is it impossible? I imagine not as I think in this world pretty much anything is possible with people but here is how I look at it:

If I were to forgive and move on from it, it requires a rebuilding of that trust and that trust must be on the adulterer's part not mine. I would expect and require that I have been given evidence that they have really faced their wrong doing or for lack of a better word, repented of it to me. What that evidence would be is hard to define but it would be clear that they know they were wrong and were sorry for it and ready to be different. Truthfully forgiveness could come without all of that but getting past it and contining with this person could not. what I mean is even in the event it was forgiven does not mean that I would continue in the relationship with the person.