Well, I guess you learn something new every day. But I never thought tipping was racist. That, however, is the claim of one American burger joint owner who is banning customers from leaving tips in any of his Shake Shack premises.
He says that this is because of slavery and claims tipping stems from a time when black waiting staff weren't paid for their labour, but allowing them to collect tips was a handy way of saying they weren't slaves.
That's an undeniably fascinating historical nugget, but it bears no relation to the real world. After all, tipping goes back to the London coffee houses of the 17th Century.
I worked in restaurant kitchens when I was younger and while us subterranean creatures were never allowed to mix with the customers, everyone shared their tips and it was, especially in the run up to Christmas, a vital source of cash.
But, more importantly than that, tipping is part of the basic social glue which helps keep a society together. You can learn a lot about someone from the way they tip. I once left a restaurant because the person I was meeting seemed to think that insulting the staff came as part of the service. I stood up, said I was going to the loo, instead went to the cloakroom, got my jacket and walked out.
There's no point arguing with such rudeness, and drama in a public place is something which should be avoided at all costs. But I wasn't going to be party to the obnoxious humiliation of a waitress who was only doing her job.
There are plenty of arguments against the custom of tipping and some of them are perfectly sound. For instance, allowing floor staff to keep tips means restaurants don't have to pay their workers a proper living wage.
It's true, also, that people in other jobs don't expect to be tipped.
For example, I occasionally have readers approach me and say they liked a particular piece - but they've never given me money.
Don't get me wrong, if anyone wants to hand me cash because of something I've written, it would be extremely rude of me to refuse. But I can't see it happening any time soon.
There are lots of things you can logically dispute - there is no real reason for holding a door open for a woman, for instance, or walking on the outside of the path.
But just because there aren't compelling, logical reasons doesn't mean we stop doing them.
Similarly, you can admire Mr Pink all you like, and try to justify and explain your reason for not tipping, but it's all for nought - because we all know that the only people who don't tip are, ultimately, shits.
If you can afford to eat out, you can afford to tip.