I would just use an app to translate. Being the polyglot doing the translations all the time is so annoying, speaking from experiance.

The polyglot should only speak up if the translations is wrong, otherwise, just let an app does its thing. That’s what I would do.

Privacy-wise, probably not that optimal, since you know… internet mass surveillance. But at least you’ll understand each other.

Use basic words, don’t use fancy vocabulary. Easier to get translated. No idioms, no metaphors just the basic words.

Btw: if one of you have a Samsung Phone, there is a “AI-Assisted” live-translation feature that should make the translations better and more accurate, supposedly.