Haha, reminds me of this one time when I met a Spanish and a Brazilian (I’m Chinese) and our conversation somehow turned into a discussion of the two languages. I asked “so how well can you two understand each other?” and suddenly a white American woman, who apparently had overheard the conversation, decided to butt in and said “he’s Brazilian! he speaks Portuguese!” with an arrogant tone in an attempt to correct my “ignorance”. And the two had to tell her “oh they know, we’re not talking about that” lol.

The point is that chances are, your coworker isn’t going to be offended by that. Just be humble and don’t behave like an arrogant American. In fact, we ended up having some very interesting discussions about Spanish and Brazilian Portuguese following that funny incident.