In Sage's case, it's quite simple. Even if the MC is/was not Sage's fuck buddy, Sage told Chad in EP8 that she cheated on him. The question is when and with whom?
There are 3 good candidates. Jacob, Anthony or JB. During the HOT party in EP7, when the MC rejects Sage again, Sage remains sexually frustrated.
When the MC brings out all the jocks, it will be John with Elena who invites Sage to a threesome. But that's unlikely because JB uses condoms. We see this in his party lighting at EP8's dorm party.
If the MC is Brav, it depends on whether he brings Sage a whiskey and if it's the right one. If so, Jacob will leave Sage alone because he is a coward. Jacob overhears Sage practicing martial arts with the MC, and at the party Sage tells the MC that he knows her well. Jacob would then be too scared to fuck Sage. So he goes to Arieth or Camila who is very drunk. Easy prey for a fearful hunter. Now when the MC talks to Ashley and then talks to Derek on the phone, Ashley goes to Derek and Anthony has to find a new fuck for the night. He doesn't know about Sage's relationship with the MC, but he does know that Sage is no longer in a relationship with Chad. Anthony likes redheaded girls. He had Arieth, Ashley, and maybe now Sage. If Jacob went to Arieth because he is afraid of the MC, Anthony is left with Sage.
The weird thing about EP8 is that all the girls who might be pregnant are wearing orange clothes. Sweet and fruity is what the MC says to himself while mixing drinks for Josy.
Image 01: Ashley and Camila
Image 02: Sage
Image 03: Josy
Image 04: Maya
It depends on our playing which girl is pregnant or not. The absolute gau would be, of course, if several girls are pregnant. This is also possible if the girls rely on birth control pills. Oops. Quinn made sugar pills out of that.