I wonder which you are --- the cheater or the cheated ? A cheater usually continues cheating if they can get away with it, and if they feel no real need for a genuine committed relationship, and often because they have a low opinion of themselves ( which we generally share ) and feel it proves something good, rather than pathetic, about themselves, to cheat.
The cheated are usually innocent victims the first time round, but to some degree masochistic and also think very little of themselves, if they allow it to happen more than once.