When someone who takes their steak super rare makes the "still mooing!" joke in a restaurant, everyone has a polite chuckle and then gets on with the business of eating their clearly not-alive food.
But what happens when the sushi you ordered comes to the table and is actually, visibly, still moving?
Because we know we'd bail out of there as quickly as we could, not poke at it with chopsticks like whoever the person in this now-viral video does.
The clip, which is said to have been filmed at Japanese sushi chain Sushiro, shows the moment a freshly prepared surf clam hasn't quite figured out it's supposed to be dead.
That's not just a wriggle, that's a full-on call for help. What is going on here?
Captioned "the tragedy of Sushiro", the 28-second video has been viewed more than six million times, with social media users comparing it to videos of the Japanese "dancing squid" dish.
But while THAT particular horror show is caused by a reaction between soy sauce and a very dead cuttlefish, there's so far been no explanation as to what's going on with the clam.
See, you'd never get this with a decent rib-eye, would you?