What's the plot again??? Spoil me (remind me)

Jiseo was hired by black-haired guy to film his BDSM sessions with the blond Sun-Yool (the actual best character.) Then he was asked to participate. Then they had a bunch of threesome BDSM action. I don't recall what happened but Jiseo ended up with black-hair and rejecting Sun-Yool. Which is fine because both of them are a bit fucked up. Sun-Yool ended up happy anyways