You never, ever, want to allow yourself to be baited into the gameplaying of a malevolent person, you never want to allow yourself to have thoughts of vengeance. But in truth, when you encounter someone who expresses an ugly attitude, there is nothing worse that you could possibly do to such a person than to let them go on being the miserable, suffering small person that they are already being, and they already have this completely covered. If you will let it be their game and not yours, It will remain so. All you need understand is that this suffering being has not yet hit the point on his or her learning curve where they recognize what a bad decision they have made in terms of who to be.
Love, Dex