Father in Law has Key to our House.

My Husband gave my FIL the key to the house. He didn't inform me of this at all! I come to realize that he is now taking showers at our house, using our washing machine, smoking in the house and dropping by whenever he pleases. He drops by every single day three times a day. I have told him we need space. My husband has told him we need space... everyone has told him we need space. BUT the man doesn't listen. Now this isn't my father so I don't want to say something and offend him...but I am sick and tired of feeling like I can't walk around naked in my OWN house that I work to pay for. But it seems like my husband can't stand up and say something And when I am mean say something I mean REALLY say something! Because obviously what he's said hasn't worked. What do I do ladies?