Dirty Doctor Deviate (1970) [Mostly soft core]
aka
Two Goes Into Two, Once (1970)
Stars: Sandy Dempsey, John Dullaghan, William Howard
A young woman consults a middle-aged marriage counselor in his office. We learn in voice-over that the man is, in reality, a predatory hack out to make a quick buck and seduce the countless vulnerable women who wander into his lair.