We know you want to come clean before you walk down the aisle, but we would have to agree with those who advised you NOT to tell your boyfriend. It would totally ruin your relationship as he would probably break off the engagement. Or he might marry you, but never trust you again. Either way, you have everything to lose and nothing to gain by telling him. Moreover, it sounds like you truly regret what happened and that is enough. It was a one-time slip, it’s not like you are a serial cheater. So forgive yourself and move on. 

 

Here are other reasons we think it is best not to tell him: First of all, it happened while you were dating, not engaged, so technically you were a free agent then. You both slept with other people in the past, so leave it at that.

Second and more important, it was done in a drunken stupor, so you can easily tell yourself whenever you feel guilty that you were not of sound mind and that you would never have slept with him sober. It was the alcohol that made you do it. As you say, it was totally out of character. If anything, you might want to ask yourself if you have a drinking problem if your consumption that night was so great. Better to go to an Alcoholics Anonymous meeting and find a female sponsor to talk to about your history with liquor than to confess to your fiancé. Even in AA, they say to make “direct amends to such people wherever possible, except when to do so would injure them or others.” You would be injuring your fiancé with your admission just to clear your conscience and that is selfish. And it sounds like you have made amends to your fiancé, on some level, by being a grateful girlfriend.

Third and most important, you say that there was nothing lacking in your relationship to drive you to sleep with the other guy. So it’s not like you need to tell your fiancé, “Look, I slept with someone else because we haven’t had sex in three months or we don’t communicate or you’re not affectionate.” There is no problem to be solved. And it’s not like you want the other guy. There is no third party.