Born with no female sex organs, bed bugs mate by using their penis like a hammer. A pointy hammer. Males just truck on in there and stab a hole somewhere in the lady's abdominal region. It's called traumatic insemination.

11. Paper Nautilus Octopus

Girls are gross and you should never touch them. Instead, fill one of your tentacles with sperm and detach it from your body. She will absorb it into her own and you'll be cootie free.