A Leopard Cannot Change His Spots(a person cannot change his or her basic character once it has been formed)
Pat, I'm at my wits' end. I don't know what to do about having Stephen clean up his room.
Didn't he promise to tidy it up this afternoon?
He did. And look at it. It's still a mess! I can't and won't keep picking up after him.
It looks like a leopard cannot change his spots. No matter what we do, he won't keep his room in order.
Please don't expect me to believe that his habits are already formed and he can't change them. He's too young for that.
OK. I'll have a talk with him and see what I can do.
Good luck. But I bet you won't get to first base with him.
tidy up = 片づける
not get to first base = 全然うまくいかない