Question: what is it called when a guy has more than one wife?
Answer: Polygamy (from Late Greek πολυγαμία, polygamía, "state of marriage to many spouses") is the practice of marrying multiple spouses. When a man is married to more than one wife at the same time, sociologists call this polygyny. When a woman is married to more than one husband at a time, it is called polyandry.