My DP is British. He's lived in England his whole life. His father is Irish and mother English. They both speak like respectable Brits.
He doesn't have any American friends. He's only visited America once - with me two years ago.
Despite this, he has a really annoying habit of using odd Americanisms in everyday conversations. For example, we were just talking and using letters in our conversation ("If you do A and B, you'll get X"), and he replied with "or you'll get 'Z'", as in 'Zee'.
I asked him what he'd just said, assuming he'd correct himself, but no he just 'Zee'!
It happened a couple of days ago too. We're having our first baby and were looking at nappies. Throughout the whole shopping trip he kept referring to them as 'diapers'.
I don't have any other active examples at he moment, but I know there has been their incidents. I'm sure it's getting worse the older he gets as I don't remember this when our relationship began 10 years ago. I think it's because he watches a LOT of American TV. Anime with American voiceovers, American dramas, American comedies, American Youtube videos, etc (also annoying but a separate issue).
I Just find the constant use of Americanisms really annoying but he thinks it's fine. I don't want him teaching our son this. AIBU?