I am searching for a movie title.

An evil mother and a mentally challenged grown son named Charles.  The Mother would ask Charles to do something evil and he would obey.  She would begin with "Charles" in a sing-songy way. He would respond with a pathetic "Yes Mommy Yes".  This was a black and white movie. It was from the 1950's (I would guess).  A scene from this movie briefly appears in "Once Upon A Time in Hollywood". It was playing on a tv set in Leonardo DiCaprio's home towards the end of the movie.  I am searching for the title of this movie.  Help!!!  thanks