Mormon Confession

Knowing the hearts of men, and their intents, and their abilities to repent and regenerate themselves, the Lord waits to forgive until the repentance has matured. The transgressor must have a "broken heart and a contrite spirit" and be willing to humble himself and do all that is required. The confession of his major sins to a proper Church authority is one of those requirements made by the Lord. These sins include adultery, fornication, other sexual transgressions, and other sins of comparable seriousness. This procedure of confession assures proper controls and protection for the Church and its people and sets the feet of the transgressor on the path of true repentance.

Many offenders in their shame and pride have satisfied their consciences, temporarily at least, with a few silent prayers to the Lord and rationalized that this was sufficient confession of their sins. "But I have confessed my sin to my Heavenly Father," they will insist, "and that is all that is necessary." This is not true where a major sin is involved (Spencer W. Kimball, The Miracle of Forgiveness, p.179).

Church authorities prying into your personal sexual life is voyeurism. You are under no obligation to tell these men about your sex life—it is none of their business. Of course you might believe that God won’t forgive you unless you give all of the juicy details of your sins to these men; many Mormons do.  If you really think God works that way then do what you need to do. But I wouldn’t if I were you.