Leaving something on your plate you dislike

There are some very insensitive replies on here.

Bytheway, as a couple of people mentioned, he could be on the spectrum. Behaviour like this is something someone with undiagnosed autistic traits could do. You would need to look at his overall behaviour over the years especially in comparison to siblings to get any hints if it's possible.

I think my reaction would depend on which of my children behaved like this. One of them, who I strongly suspect is autistic, has always had an aversion to certain foods and has equally strong reactions to anything that she finds wrong. She can't help it but as she has become older, she is getting better about how she reacts and we have become better at how we handle it. I know that if I was critical of her reaction, things would get worse so sometimes, least said, soonest mended.
One of my sons hates mayo but always checks that dishes don't include it and both of them would certainly know I didn't appreciate their ingratitude if I was paying the bill or I would tease them until they came out of it which they would.
I can't eat food that has baked bean juice on it or if it has coriander on it but I will usually ask if I think it might be a problem. If my food turns up with either ingredient, I will send it back if it hasn't been included in the ingredients. I don't sulk or get angry, I just politely explain why I can't eat it and ask them to change it. Most restaurants are happy to oblige and I always make my gratitude known.

It was poor behaviour on his part, and I would have called him out, even if he is an adult.

Also, coleslaw is almost always served with fish and chips here! Often it is served in a little container on the side, especially with take out.

Different things bother different people. There is a lot of intolerance on this thread, which is ironic considering that people are blaming the son for not tolerating the coleslaw .

Mostly that sort of thing wouldn’t bother me, and I would just leave something I didn’t want to eat; but I loathe the sight and smell of eggs, and if I am served one I would struggle to pretend it wasn’t there. It has happened when I’ve ordered gammon and specifically said ‘no egg’, and they appear unordered on breakfast plates. I smile, say ‘Oh, I ordered no egg - could you take it away please’. I don’t think that’s childish or ill-mannered. I don’t want to risk piercing the yolk when eating around it - just the thought of that is making me gag.