That is such a garbage deal for Valerie. Basically paints her and Serenia as "seductive women" and makes it so that the men "can't help it" because they fell in love with different people...also, would Serenia even want to entertain being seen as Kylus' mistress, even if it's only rumors? She didn't ask to be protected by the prince, and she values Valeri's friendship enough that she wouldn't want her to suffer rumors because of her, right?
The men basically get off scott-free, while the women can have their reputations ruined...I know that they could wave it away later by having the crown prince spread rumors he's in love with someone else and have Valerie and Kylus marry (they can just say, "who came up with those rumors, it was a misunderstanding" bs) but Valerie will suffer the most in the interim...bothered by invitations, can't make any new friends, her family will also get bothered with invites...like, c'mon.