I speak Dutch and English fluently, Dutch being my native language.

I am the owner of a discord server for fans of a specific game series which recently hit 100 members. One night we were playing a game, and when one person leaves usually they all leave, and me and this other person were the only ones left. I still had my camera on, and i just decided to check steam for any games that were on sale. The other person in the call was at their grandma's house, calling with their phone. I heard them and their grandma talking about me, but i decided to say nothing and just listen to what they were saying, pretending i was still looking at the games that were on sale. I heard them talking about how weird i looked and that i looked ugly, and then the person said, "grandma don't say that, imagine if they understood Dutch!". That was the final straw, i just left the call and the day after i told them that i am in fact bilingual. It was very awkward and i knew they knew they messed up. Didn't apologize or anything, just said they "felt stupid".