The Heat of a Thousand Suns 1965 ( 5.8)

A young man from the far future, bored by his surroundings, blasts off into space with only his cat and some robots for company. On a distant planet he discovers a serene, tranquil culture and falls in love with a girl. The story follows his problems adjusting to their sociological standards and customs where family units are comprised of sexual groups of eight people.