James van der Beek in Rules of Attraction
Can't believe nobody's posted this one yet! Jamie-boy is jerking his meat as he reads a letter from his secret admirer. Also some great scenes of him screwing a meaningless party girl whom he described in an earlier scene as having "great dick-sucking lips"
In the remake of 'Psycho' (which was actually pretty bad), Gus Van Sant - the director - had Vince Vaughn, as Norman Bates, jerk off while watching Marion (Anmne Heche) get undressed before her shower... he watches her through the hole in the wall behind the painting. It's pretty fast and you don't see his cock, but you hear him breathing heavy and gasp when he cums.
Sorry about that. I meant Vince Vaughn. I looked up who starred in the Psycho remake and it said Robert Loggia. My mistake. Who is Robert Loggia anyway?