Rape Is a Circle (2006)

Two girls hitch a ride from someone they think they can trust. After all, the driver is a woman. They endure humiliating perversions and excruciating pain. Their friendship warps as they are forced to perform sexual acts on each other for the twisted amusement of their captor. Escape is no easy thing to accomplish - they know they only have one chance because if they fail they will be killed.