If two partners love each other, I believe that their future shouldn't be destroyed by one mistake. However, an unfaithful partner only deserves a second chance if they feel true remorse over what they did. If the cheater doesn't feel sorrow for hurting their "loved one", then they don't deserve to be in a relationship. The cheater must be willing to show the betrayed partner they still want to be with them over anyone else. This means the cheater must accept any conditions the betrayed partner feels are necessary. This includes sacrificing the right to privacy, living by curfews, constant check ins on whereabouts, et cetera.
There are arguments that cheating is a sign of major relationship issues. I couldn't agree more. However, these relationships issues may still be fixable. As I said earlier, cheating shouldn't mark the end of an otherwise amazing relationship. But only if both partners are willing to commit to the long and painful process of rebuilding from the ground up.
Cheating is a one-time only mistake however. The betrayed needs to make it very clear to the cheater that their mistake won't be tolerated again. It can't be. My policy on cheating is "once is a mistake, twice is a habit".
Being cheated on is the worst thing that can happen to someone. But the rewards of rebuilding your relationship and finally moving forwards are immeasurable.
An unfaithful partner deserves a second chance to make things right. However, a serial cheater needs to be dropped like a rock. Everyone makes mistakes, even an unfaithful partner. If that person didn't learn a lesson the first time, then there's a pattern to the behavior and something else must be done to solve the problem.
Personally, I do not believe an unfaithful partner deserves a second chance. I think a person who is inclined to cheat once, is inclined to repeat the error again in the future. I think it is a clear sign of major issues in a relationship and I personally wouldn't try to spend any more time trying to mend it at that point.