Momo

Momo is a movie starring Christian Clavier, Catherine Frot, and Sébastien Thiery. The Prioux family finds a stranger in their home, a deaf man named Patrick who's pretending to be their son.
One evening, when they come home, Mr. and Mrs. Prioux are astounded to find that a certain Patrick has moved into their place. This strange young man has returned home to his parents in order to introduce his wife.