'Mother's Day' trivia and fun facts
The movie's poster is a parody of the painting known as 'Whistler's Mother'.
The woman with the dog at Trina's party is Charles Kaufman's mother. The man snorting cocaine is Charles Kaufman's father.
The house used in the film was an actual house in the woods of Newton, New Jersey. No one had lived there for 15 years prior to filming. The previous owner of the home was murdered there.
Charles Kaufman, in the director's commentary, said that a very ironic thing happened during filming: an actress who played one of the victims and one of the actors who played a son hit it off and starting dating when not filming - even though his character terrorizes and brutalizes her. Concerned that neither would be able to project the sense of terror needed, Kaufman asked them to postpone their relationship until after the film wrapped. They complied.
Much like the scene at the seminar, the guests at Trina's party were crew members. This was done because of a money issue.