The angel of the LORD also said to her: “You are now with child and you will have a son. You shall name him Ishmael, for the LORD has heard of your misery. He will be a wild donkey of a man; his hand will be against everyone and everyone’s hand against him, and he will live in hostility toward all his brothers.” Genesis 16:11-12
This is who the Muslims claim as their ancestor.
That’s an open and shut case for monogamy right there isn’t it?