Birds do it, bees do it....apparently even leopard slugs do it, and you would not believe the kinky shit they get into.
Check out the video below, accompanied by tasteful music and narrated by noted slug porn fetishist David Attenborough.
It all begins with a slime trail:
"suddenly, the pair release their hold on the branch and begin to slide downwards on a rope of mucous..."
"each everts its male organ from just behind it's head. these grow longer and longer, then they too begin to entwine..."