Two coworkers have this habit of speaking to each other in the office in Italian.
The one spent twenty years there, and 'forgets' to speak English. The other one is just Italian-Canadian.
Listen -- I know that game. I play that game. I speak Dutch to my family when we don't want other people to know what we're saying (especially little children). But I would never, ever do it in a work environment.
Even though I play that game myself, it's incredibly rude.
It is even more rude in an office setting, when we're all supposed to be fucking professional. So annoying.
One of these days when they do it again, I just have to offer up a comment in Dutch, even if there are no other Dutch speakers here, just to put them on the receiving end.