Being unfaithful ranks at the top. When you become a couple you commit to being faithful to each other. The man cuts off other females from his life and its only fair that the female does the same. The relationship consists of two people, not just one. People often feel betrayed and lied to, heart broken when they are cheated on. One night of pleasure with a "hot" partner, and running the risk loosing the one you love is not a gamble that anyone should decide to take on.