The act of infidelity between two partners in a marriage, or an adult relationship. Cheating is a very strong word and should NOT be used by LG's and LB's in highschool when their partner is sexually involved with someone else. If someone is unfaithful to their partner, they are to immature to be in a relationship! Grow up first, before you hurt someone.
A LG came to me crying, "I caught Colten cheating on me." I responded, "You're thirteen years old! What the hell are you talking about."