I sometimes say 'oh yeah' in a high pitched way if something has surprised me. On Friday I said 'oh yeah' and my boyfriend mocked me and said 'oh yeah' back. I was surprised he did this but let it slide. He did it again yesterday and said 'oh yeah' after I said it he then said it again later on and this time I said 'oi you have done that again now'. He did it again and said he was only joking. Then he said 'oh yeah' subconsciously in conversation and stopped himself which I said see you say it too.
When I got home I messaged him to tell him it was unkind of him to mock me and that I don't have to put up with this behaviour from a partner. He said he was only teasing and apologised and said he didn't mean to cause offence. He said he guess he did it because he thought me saying 'oh yeah' was cute and that it reminds him of when his young daughter does it.
I said I can't change my appearance or mannerisms and he said he doesn't want me to change anything about myself as he loves everything about me and he said that deep down I know this. He said he thinks the world of me and respects me. I accepted his apology and will monitior if it crops up. It just disappointed me as we had such a lovely day too. I have never mocked him for his mannerisms or his autism and ADHD.