I'm an American living in Japan and the this happens quite a lot - even among friends who I'm pretty sure mean no harm. It seems like a lot of people have this

I'm an American living in Japan and the this happens quite a lot - even among friends who I'm pretty sure mean no harm. It seems like a lot of people have this very strong "foreigner = English" mapping in their head. As soon as you're outed as "foreigner" for any reason, you get the English (even if you're proficient in the local language). I definitely think it's disrespectful to switch languages on someone like that, but a lot of people just don't seem to think about it. Multi-lingual conversation manners are not commonly talked about!