Just say "I don't want to hurt your feelings, but BUTT OUT." Of course, say this after you've had enough vodka (power juice).
From Michael Berg:

Every person has a unique connection to the Creator that can never be extinguished, and every person has a great soul that can manifest important things in our world. To make a person feel less than they are because of something inside themselves, be it faith, race, or sexual orientation, is the greatest sin of all."