But that's the thing, DPC usually doesn't give a fuck what his supporters think. If it fits the story that he built up in his head, he's gonna do it. You think that if the Rusty banged Jill story fits in his plans and how he planned the story to move on, he's not going to do it because of the outrage of the Jill fans? I don't think so.
As for Chad and Sage, I think that Sage was enamored by him whenever they met and Chad needed something to hide his homosexuality, so Sage was his answer. Do I think that they've had sex before? Absolutely. But here's the thing, it wasn't enough for Sage and he preferred the company of Troy or whoever his lover is. So that forced Sage's hand to look for a fuckbuddy and somehow she ran into MC who already wanted to hit that.
Do I think Sage has had other fuckbuddies? Probably. We know from Jacob that Sage's parents are influental people and that she's doesn't have a very good relationship with them. It might be something connected to her behavior regarding the fuckbuddy thing, but that's a long stretch.