i know of some bi/multilingual families in the us who’d talk to each other in their native tongue when they didn’t want the kids to know what they were saying.
i speak my dad’s native spanish as well as dad’s learned portuguese, but i don’t speak the polish or norwegian from the other side of mom’s family. (she’s also latina but doesn’t natively speak spanish)
however, i’m learning the two i don’t know, and practicing polish (the language my mom does know) with her
I went to a Sikh wedding once, and spent the day hanging about with a bunch of the guests, all of whom were British or Indian. I spent the whole time amazed that they’d seamlessly switch between English and Hindi, apparently without noticing.
code switching is awesome. sometimes i’ll hear bilingual hispanic people being like “oh, by the way, ya has visto squid game (have you seen squid game yet)? it’s so good”