https://www.newscientist.com/article/2521744-male-octopuses-have-a-favourite-arm-that-they-mostly-use-for-sex/

Despite the fact that I am evolutionarily quite distant from octopuses, I also have a most precious arm which I endeavour to keep safe and to prevent it from getting damaged or bitten off by a predator.

Male octopuses have a favourite arm that they mostly use for sex

The third right arm of male octopuses has a specialised role in mating, and the creatures take extra care to avoid damaging it or losing it to a predator

New Scientist
@Spoon man, I hope that Haruki asked for consent first
@dharmadan you 'raise' a very important question here. I sincerely hope that this is not an example of octobuse - or should that be 'octabuse', I can never remember.
@Spoon In the interests of harmonious cephalopod / human relations, I did think it was worth running it up the flagpole. It can be a sensitive topic.

@dharmadan I am in complete agreement here and I am sure you will recognise that despite the evolutionary gulf there are certain inalienable similarities.

For instance, whilst the octopus has no brain, humans, mostly, have one, but don't use it.