My partner and I are from two different European countries that speak different languages.
When we wanted to marry in the country of my partner, both our (catholic) churches needed to sync. They did so in their common language: Latin.
That was a fun surprise.
similar experience led me to start learning Latin: once travelled to an other country within Europe and the priest in the companion asked directions from a local in Latin.
That’s pretty cool. What kind of things were your respective churches communicating about?
My spouse and I lived in London, but we both come from (other) European countries, so for our wedding, three countries and four languages were involved: the church's forms are all both in the local language as well as in Latin.
This is no different than hundreds of years ago, and it works well. Thanks to Latin, the church's _lingua franca_.