Who exactly would have been hitting on her in the last two years? We've seen how ballistic Chad goes at the appearance of infidelity (while not caring a jot about Sage herself). We've also seen the jocks remember the MC because he was "making a move" on Sage. That strongly implies that random guys do not throw themselves at her very often, otherwise the MC wouldn't stand out.
This is further backed up by the way Jacob reacts if you make out with Sage at the party. Despite being in a private party, he will force the MC to knock it off and tell him it is a mistake in no uncertain terms. Even Tommy is impressed simply because the MC
intends to bed Sage. There's no reason for that respect if guys are constantly propositioning her, not when the MC hasn't done anything with her yet.
Now you could say that was all because the MC was too public; hitting on Sage happens all the time, it's just done in secret. That could explain why the jocks don't normally notice it, and why Tommy was impressed. Fair enough. What it wouldn't explain, though, is Sage. Again:
View attachment 751495
She isn't saying guys don't hit on her, she's saying guys don't normally turn her down. Well, unless we believe she's had a long string of other fuck buddies before the MC, we know the last two guys she threw herself at - the MC and her own boyfriend! - turned her down. Repeatedly.
I don't think Sage had a string of affairs; her own actions (and those of the other HOTs) suggest the opposite. So how can she still see herself as irresistible? Beats me. She may have been popular in high school, true, but that just means she should recognize she's in a long dry spell now.
That's why I think this is just sloppy writing by DPC. He wants the drama that comes from Sage being in a relationship, but refuses to show such a relationship. Maybe he's worried about NTR, maybe he wants to keep Chad from seeming sympathetic, who knows. I just know the way Sage is presented does not match the events we have seen, and at no point have any of the characters in the story acknowledged that dichotomy.