My baby speaks like a gangsta?

Her baby daddy has a potty mouth. I said to him not to talk like that cuz she mimics everything and he was like she's a baby she won't understand. Except she's 18 months old and very vocal and now she's swearing like a sailor. I tell her not to throw food, I get an eff you, mummy. She builds a tower of blocks that falls over, I hear her scream, effing hell. Now, her baby daddy is all remorseful cuz he gets upset when she tells him to get effed, but what do I do to get her to stop cussing?