Did you know that some sea slugs lose their penis when mating but it grows back again? Apparently this has been observed in the sea slug Chromodoris reticulata.
This interesting article led me to making a comparative table of human and sea-slug sexual activity for your edification. Who knows, you could be in a pub quiz one day and it might come up (a question about sea slug sexual behaviour might come up, what did you think I meant?).
So, luckily human sex is more fun that sea slug sex, even though we can’t change sex at will. We can also last longer than sea slugs if we have the right method.