In French, you can say "Très joli derrière" to mean "Very nice butt." Another casual way to express it is "Très beau cul." Keep in mind that the context and the audience matter, as some phrases can be more informal or potentially offensive.
C'était trés bien
Hello, BUTT FACE!!
très jolie musique
"C'est très bien ici"
You don't, it's never a pleasure meeting somebody who's French.
"vous avez un corps magnifique"
Ses amies sont très polies.
you be nice to them, say something like hey sexy your hot i bet you have a nice butt and then she will like you and show you
I have no clue but I would search for a translation site on google.
abouter baiser.
Bela bunda !
you say 'agréable'.