The ending made me feel sick. While discovering some dude's porn art account is damaging, it's waaaaay more damaging for a woman's homemade selfie porn account to be discovered. And while Ji-ah used Suhyun's account to blackmail him, she made it mutually-assured destruction with her own account and used it just as an excuse to get close to him (with sex involved, so yeah, that's still slimy). Without this shared secret, Ji-ah would never have had an angle to get his attention, and that's what she wanted and what she got.
On the other hand, Seola's manager doesn't have the same excuses. He already has a relationship with her - one where he has control over her career! It would be life-changing whether he revealed it or not, and as I said before, it was far more dangerous. There's no indication that he was in the same dangerous situation, either, all I can see him needing blackmail for is getting down to shady shit.
So in the end, even if the author didn't mean for it to be interpreted that way, I can't help but feel in my gut that this character that we know and like was probably exploited sexually until she gave up and called it a relationship. Fuck. I need a sequel that proves me wrong (or fixes the situation), because it's fucking me up every time I remember.