It's bad to practice polygamy.
Dave who is already married is hanging out with Susan who suddenly asks him to marry her.
Dave wants to respond to the marriage proposal.
Dave tells Susan that he cannot marry her since that's both immoral and illegal.
Dave tells Susan that he would be honored to be her loving husband the rest of her life.
Dave's wife is happy to know her husband is a loyal and faithful man.
Dave's wife is devastated to learn Dave has married someone else.