Do you want to know why people think Rosa looks sluttier?

Her outfit looks more like what a dancer in some kind of older society would wear, the kind that put on shows for people.

Rydias looks more like a One piece swimsuit, and I hardly think you go to the beach and think "Oh that girl in a one piece swimsuite is a total ho-bag".

Don't get me wrong, I don't think Rosa looks slutty, but if I had to say which one looked Sluttier, it would without a doubt be Rosa.