This falls in the list of things I didn't know I didn't want to know, but now know, and know I don't want to know. Oh no
If you've never seen this video of leopard slugs mating, you should check it out. It really is rather beautiful!
Huh, TIL that not all slugs use love darts
The love dart is not a penial stylet (in other words, it is not an accessory organ for sperm transfer). The exchange of sperm between both of the two land snails is a completely separate part of the mating progression. Nevertheless, recent research shows that use of the dart can strongly favor the reproductive outcome for the snail that is able to lodge a dart in its partner. This is because mucus on the dart contains an allomone (pheromone-like) compound that promotes sperm preservation mechanisms in the female.
Who, Slug? You're waiting for fucking Slug?"
"No! I mean no, uhh, yeah."
"Oh no, you're... You're fucking kidding me."
"He's so hot."
"Apophallated" is now in my vocabulary of insults. (To be used with caution: if they reply "Don't kink shame" then I instantly lose.)