I have a little 3 year old boy I called Jeckyl & Hyde because he was an absolute treasure for me all day then was somebody I don't even recognize in front of his Mom. I think I've cured him of this behaviour but I would talk to him about 10 minutes before she arrived about his behaviour as some of you already mentioned. Children really have to hear what is expected of them over and over again before they get it.
He isn't going to behave that way in my home because he's still at daycare and I've made that clear to him. I'm sure his Mom is grateful for his behaviour change recently and I would have loved to throw him out the door at her every day at pickup time but she likes to stand and chat with me. It is so nice to have adult conversations during our day but not when the child is putting on an Oscar winning performance at her feet!