I've been guilty of doing this to my German friends, as well, but it's because I consider their English almost native level. It's the same to me as pointing ou

I've been guilty of doing this to my German friends, as well, but it's because I consider their English almost native level. It's the same to me as pointing out to a Texan that I find their pronunciation funny. In a strange way it's a compliment to them, but after reading your post I will remember to be more thoughtful about how things like that could be perceived.