No, seriously, I just watched this. Yes, it's as nasty as it sounds.
The Husband and I watched this special on PBS with David Attenborough where he shows how slugs mate. It's incredibly replusive and yet somewhat cool at the same time. I wanted to vomit and applaud at the same time.
This definitely makes you think Nature can be really, truly fucked up sometimes. As if platypuses and Republicans weren't enough. Dah-boom cha! Thanks, I'll be here all week, remember to tip your waitress.
Anyway, did you know this interesting fact? Slugs are hermaphroditic and when they mate they're all about both of them sticking penises in things, which you'll see from the video if you watch it (or you just have to take my word for it). Their foreplay involves lots of biting!!! HOW RISQUE!!! So anyway, sometimes after sex one of the little boogers will be just a little too into it, and he'll CHEW OFF THE OTHER'S PENIS!!! There's actually a word for it, apophallation. I mean, seriously, the things you learn. So on the internets there's a video of a slug chewing off and eating his own penis. It's here and it's just as disgusting as you can imagine. Or if you don't want to imagine you can watch and see for yourself.
In closing, keep this information in mind. You'll be a hit at parties.