No, but I've done the cheating. Worst mistake of my life. Was so guilt ridden that I drove to her work 5 days after it happened and told her she can't be with me because I'm an unfaithful piece of shit. But, we talked it through and came out stronger.
Do what you feel is best. But personally, I'm not strong enough to stay with someone that has betrayed me in such a way. Though I've done it myself, I just couldn't handle it if it happened to me - if that makes any sense.