There aren't many sadomasochist characters in movies and film, are there? I can only think of two off the top of my head. One is a character who briefly appeared on HBO's Six Feet Under. He dated the main woman, I forget her name. Brenda? She was turned off when he told her he was into BDSM.
The other was an online critic in the HBO show Entourage. He was going to write a negative review of Vincent Chase, and to stop him, the entourage sent a few porn stars with strap-ons to stop him from running it.
Neither one of them were particularly flattering depictions of submissives. Can anyone remember others?