Human mating behavior is not so different from an Indonesian octopus. The prelude can include flirting and passionate hand-holding, but it can get rough when macho males jealously guard a female's home and strangle rivals.
The photo above right shows octopus sex, including the males specialized mating arm. The secrets of octopus mating have been hard to uncover, since octopi are so secretive. The current study came as scientific voyeurs hovered over the homes of shallow reef octopus and watched until they had seen enough. Special secrets include small "sneaker" males that mimic females and try to slip past other males to get to a willing female.