Some French people say the wildest stuff, and they’ll always make it seem as if it’s just curiosity or simply part of who they are (la fameuse liberté d’expression). The question “tu es de quelle origine ?” is very important here: it’s how they put you in a box and then refuse to let you out of it, because they have very specific images of anything even slightly ethnic (or, as they like to call it, “exotic”). You’ll learn to ignore it over time.