So was I, though I was mostly discussing the blackmail possibility.
Not to me. What changed in the week that convinced Chad to throw in the towel?
He clearly had no interest in Sage for a long time, yet he only dumped her in Episode 6. If he didn't need Sage for cover, there was no need for the charade at the start of the game; it's not like she confronted him with any new information about the affair since then. If he was just using her for her family connections, there's no need to dump her at all. Sure, she didn't get him reinstated, but that doesn't mean she wouldn't be useful in the future (to say nothing of how dangerous she'd be as an enemy). Above all, if he cared about keeping Sage, why the hell did he give her that lame peck on the forehead in Episode 3?!
It seems overwhelmingly likely that Chad was only dating Sage for appearance's sake. Mel told Chad something that convinced him to drop the act in Episode 6. The question is what she told him. It's not blackmail, and it's not that Mel and Chad can finally be together. So what was it?