The movie with a normal girl, normal boy and a rich man?

the boy wants that girl, but she's in love with that rich man.. and when the boy is talking to that rich man, he tells him how many smiles she got, and then the rich man tells the girl about it, but he doesn't says the boy told him that, and then she smiles, and asks the rich man, which smile was that, and he doesn't know, and that was the moment she found out she made a mistake bout choosing that rich man instead of that boy.