And there it is, Max's reasoning for why her behaviour is acceptable - she views herself as selfless.
Max has the self-confidence to view herself as attractive and desirable, she sees sex and orgasm as a potent and universal form of pleasure, and the pursuit of pleasure as an intrinsic good. To Max, it is self-evident that, by being as promiscuous as physically possible, she is being altruistic.
Adding another layer to this is the fact that she's currently playing Freddy. Is Freddy an attractive, desirable character? Is Gina doing a poor job of playing Daphne by not wanting to sneak off to make out with him?
Beauty - and sexiness, and desirability, and appropriateness - are in the eye of the beholder, it's true. But, of course, authour intent matters as well. If, for whatever reason, you are emphatically, viscerally, disgusted by Julia Roberts' face, and you can't view Pretty Woman as anything other than a gross-out horror movie... quite frankly, you're in the wrong. You are watching the movie wrong and that's your own damn problem. Perhaps you shouldn't be watching Julia Roberts movies in the first place.
And, of course, there's another layer that this is a communal fiction, with its participants having differing opinions and differing amounts of information about the characters they're playing. And there's the other other layer of differing versions of Scooby-Doo itself - original Freddy is a different character from Mystery Incorporated Freddy, who is a different character from live-action Freddy as portrayed by Freddie Prinze Jr.
And yes, one of those is Y and one of those is IE. And Puerto Rican, incidentally.