Watch The Mating Habits of the Earthbound Human for Free: How to Stream the Movie Online at 123Movies. . David Hyde Pierce, playing an alien (credited as infinity-cubed in the opening credits), narrates a courtship in a late-20th century American city as an extraterrestrial nature documentary. The relationship "footage" is played straight, while the voice-over (with its most often wildly inaccurate theories) and elaborate visual metaphors add comedy.