To be annoyed at DS getting annoyed

[Dracomalfoysmum]

DS (age 11) hates seeing DD (age 8) biting her nails. He gets really really would up by it and is constantly telling her not to bite her nails and can get completely distracted and distressed when he sees her do it! It is a bad habit of DD but, although I do gently discourage DD from doing it, I also don’t think it does anyone else any harm and she is otherwise happy. I’ve tried to explain this to DS but he continues to tell her not to do it as he says it’s disgusting and spreads germs! He says it harms his eyes to watch DD do it!! DD is now getting really wound up by DS (although at times I’m sure she’s doing it on purpose to wind up DS-normal sibling behaviour I suppose!). I then get annoyed at DS getting annoyed at DD and it feels like a viscous circle!!

AIBU to get annoyed at DS re his behaviour towards DD? Anyone had similar situation and how did you resolve?

You need to tell him to leave the room when she's doing it if it annoys him so much, rather than trying to get her to stop. 'You can not like that she bites her nails but you can only control your own actions'

He says it harms his eyes to watch DD do it!!

What would he do if he was in a public space?

He is in control of his own eyes. He can shut them, look somewhere else, leave the room.

It would be good to help him come up with strategies for the times when he may be stuck somewhere for a while with a stranger who does this - a plane journey for instance.

although at times I’m sure she’s doing it on purpose to wind up DS-normal sibling behaviour I suppose!

I pull him up every time I see him get on at her but it doesn’t stop!
I hope you pull DD up just as much for doing it on purpose. It sounds like something he genuinely reacts to and needs help with, purposefully provoking a deeply uncomfortable feeling in him isn’t on.