Bernard Picton, curator of marine invertebrates at the National Museums Northern Ireland, explained: "The genital apparatus is on the right hand side of the body. So two nudibranchs come together and one faces one way and one faces the other way, with the right hand side of their bodies touching.
"The penis from one fits into the female opening of the other one, and the penis from that one fits into the female opening of the first one, if you see what I mean.
I call it the sea slug 69. Thank you Bernard Picton! And thank you Rebecca Morelle, who reported this in her piece for BBC news.
I know. Some of you are thinking, sea-slug sex? That's so yesterday. And it is. Because today? Today we know that these little fuckers shed their dicks. You know, like fur or snake skin. They enjoy wild hermaphrodite slug sex for anywhere between a 'few seconds' and a 'few minutes'
after which the creatures would push away and shed their penises, leaving them on the floor of the tank.