Oh God, that poor animal, and poor you too. How horrible.
I've noticed that a lot of N-ish folk seem to get a real kick out of carrying on like total twits in restaurants. Just exactly like Mum is describing, and also they looooove to get all picky and snotty about the menu, with the waiter or waitress, who of course has nothing to do with the menu selections, but if the N-ish one can annoy the waiter enough that it shows, then they can pretend to be justified in stiffing the poor soul for their tip.
Egad, it's Memory Night. I was in a restaurant with a date - this is about, what, six years ago... we were in a booth, near my old college campus, sentimental visit to a restaurant I'd loved when I was a student, and it still existed six years ago. Anyway. Next booth to us is occupied by a family of utterly obnoxious twit jerks, mom and dad and spoiled brat student boy. The kind of people who deliberately talk at the tops of their lungs because they know their conversation is much more worth hearing than anyone else's... so anyway they order their meals, and the food comes up, and they sit and yap for 20 minutes, then turn to their plates... surprise, surprise. The food is cold.
they call their waitress over and castigate the poor girl until she cries. They summon the manager and carry on about her poor service and the lousy cold food and this and that and god knows what else. I'm getting madder and madder...
So I get up and walk over to the cash register, out of sight of these jerks, and when the manager heads back over I buttonhole him, and I grab the waitress. I tell him, in her hearing, that I have been in the next booth the entire time, and I know for a fact these creeps sat and gabbed for at least a quarter of an hour without touching their plates, and the waitress is not at fault, because she waited on me too and our food was good and piping hot.
They both thanked me, and I said look, those jerks were trying to get her fired, just to prove they could, and I'm damned if I was going to let that happen. I've supervised plenty of people in my time and I despise bullies, etc. Then I gave her a couple of bucks, in front of the manager, and told her, they're going to stiff you on the tip, they're probably going to demand the food for free, and you deserve a tip at least.
Then I went back and sat down and spent the rest of the meal stifling giggles as these @$$h__e$ went on and on about the waitress, etc., while - of course - continuing to stuff their faces with the food they'd whined about.
Good thing I'm not in the restaurant business.