The Transgressions of Tina (2008)

Unbeknownst to her shifty best friend Liz and her abusive boyfriend Rick (who are having an affair with one another), seemingly simple college coed Tina is keeping some secrets of her own. Upon her abrupt disappearance, Rick and Liz set out to quickly get to the bottom of things only to discover they've opened up a veritable can of worms when they find that a sociology project has led Tina to the shady world of sex-for-sale. Tina's mother, aware of the abuse suffered by her daughter at the hands of her potential son-in-law, is convinced that Rick is responsible for Tina's disappearance and is determined to see him pay, one way or the other...