I understand where you are coming from, but I respectfully disagree based on the available information. It is clear that even though Chad is gay he did have sex with Sage at one point before stopping suddenly. This sudden abstinence is what caused the problems in their relationship. If they never had sex at all I doubt that Sage would consider him a boyfriend in anything but the most superficial sense of the term. Chad was obviously in denial about his sexuality at least until he fell in love with his boyfriend and couldn't deny it anymore. It was at this point that he began to make thin excuses and pretexts to avoid intimacy with her. Again, if they never consummated their relationship they would discuss their difficulties in an entirely different fashion. But I think that the point of my original post is that I don't care either way. I just dislike slut shaming and other denigration of women based on adult consensual sexual activity. Whether or not Sage slept with one Chad or a hundred in the past doesn't make her a more or less viable love interest. Only her relationship with the MC can do that.
I do agree with your overall post, about slut shaming. I am not one to discuss morals but is choice of zoey to fuck anyone, hell our mc can be mega chad fucking almost half of the main cast before settling off for a one in last ep.
To surprise you, the onset of failure oc this relationship is chad not coming to realization that he is gay is abysmal. You have to play the game again, I dont recall all stuff but this should help you in order to deduce as to how sage has been used as a trophy for chad to cover up and maintaining status as CHAD in game.
1.Chad and Sage talk in ep 3 or 4 after chad gets kicked of the president title.
2. Flashback of the sage and chad in the game in ep 5 or 6.
3. Latest talk in last ep between sage and mc.
Sage was more or less a title for Chad, and sage realises it in the end and forgives him because of it maybe.