I think you kill an octopus by stabbing it between the eyes.
The tentacles would still wriggle - it’s residual nerve action - just as they would cut from a living octopus.
Eating the tentacles would still be perverse and decadent, but at least the octopus would suffer no more than the usual death.
“Well, y’see, this is a real special pig.”
There’s a tradition among fisherman; to eat the beating heart of the first tuna you catch. I have no idea who or why the tradition was started. UGH!
https://socalsalty.wordpress.com/2011/08/26/video-eating-the-heart-of-a-tuna/
It’s not macho, it’s gross.