Like I speak English and Portuguese, learning Dutch, and (not doing it for the sake of a primarily English-speaking community) but I will often switch between the two, like saying “Bom dia/Oi” to someone or “Tchau!”
I may also falar assim and I don’t do it to show off, it’s just comfortable pra mim. I will mix in a few português words. (Not exactly like this but YKWIM, maybe).
Being English, I’m stubbornly monolingual (aside from some leftover schoolboy French), so when I was invited to a Sikh wedding I was genuinely amazed by all the guests just flowing between English and Punjabi as if they were the same language.
It’s not just them, a lot of people across the world speak a mix of english and their native tongue.
Even seen philipino subs coming to the reddit front page? They usually start with an English phrase and end in tagalog.