You’ve given some food for thought alright! When you cheat someone you’ve committed a sin and that will stay with you whether or not you confess. You owe your partner a confession and he/she has the right to decide whether they want to stay with you or not after that. Otherwise it amounts to a double betrayal. More often than not, it is only the first act of digression that makes you feel bad and if you do not confess you are bound to repeat what you did. The human defense mechanism is so strong that you’ll cover up what you did and justify your doing it, over and over again if you do not confess.