I don't think she actually wants to makeup with Maya, she's just joking. The real purpose of that scene is not saying us that Sage is horny and wants to makeup with Maya, but introduce the dialogue.
S: Have you kissed a boy?
M: Yes
S: For fun?
M: No, it was real.
S: So, you aren't 100%?
M: I don't know what I am.
S: Must be a hell of a boy.
M: It was Jack.
Now, Sage knows that somehow, something real happened between MC and Maya, not only "MC had a crush on Maya and Maya refused him because she's lesbian" (what I think Sage believed so far). If MC is not into Sage's path, this is just gossip. That scene if not even needed, is just filling material. BUT, If MC is into Sage's path, it means that somehow, Maya enters into MC's "Exes" category, and some jealousy can be expected from her, the same way she may be jealous for the fact that MC invited Zoey to the party or if MC flirts with other girls.
About kissing Josy, it's like the HOTs and daughters kissing each others during the game of "spin the dildo", as a dare and to turn on the boys looking. Sage is playing there and trying to turn on MC, both if they are fuck buddies or not. That's why her first interaction with MC is asking him if that costume is for turning on girls with his "hot body". Again, that interaction makes sense if MC is into Sage's path, if not is just filling material.
The problem with most of the scenes of a given girl is that should work the same if MC is following the route of that girl, and if not, because DPC only can create a limited number of specific scenes for any given girl. Some of the scenes and interactions with Sage only make sense if they are fuck buddies and almost couple. I don't think that makes a lot of sense that Sage flirts with MC during the party in several occasions and try to turn him on, if MC rejected Sage, specially if it was after the scene when he tells Sage that he wants to have dates with her and have something real together, not only sex.
DPC needs that Sage and MC remain friends for the sake of the plot, but character-wise, a proud girl like Sage that also has been dumped by another guy a few days before, wouldn't react the way she does in that scene. She should react like Quinn, simulating indifference, or even with repressed anger, and would not continue involved with MC in party planning and would not interact with MC in the party. But again, it would go against the plot, so we have to suspend the incredulity if MC rejected Sage. I think that Quinn's, Bella's or Jill's path after MC's rejection has way more sense. They react the way their characters should react, according what we know about them.
