I’m curious, not that I’ve got anything against this. Of course escorts can ask about potential clients’ nationalities. But I do wonder what might be the reason behind it. Do they not accept clients from certain nationalities?
Probably fir the same reason clients may prefer different nationalities, Body types, hair colour, age etc.
Escorts are people with the same rights to choose who they wish to see just as much as you have the right to contact who you would like to see.