The professor knew Jaeha wouldn't accept breakup so he tried to blackmail him with that picture. I guess, professor has done this before?
Its very common being heartbroken at least once in your lifetime and I don't see drama queens everywhere using and hurting people acting annoyingly. That doesnt serve me as a excuse and is not like to call him broken either, for sake of god. He has a ex boyfriend who turned out to be a jerk, fresh news, wow.
Sorry I answer the wrong comment
Yeah, its obvious, he as douchbag. Beware of assholes, ladys and gentlemen, theres a brunch out there.
If you look again at the photo of jahea,
It shows him from the perspective of the professor and because he's dick was inside him from that position ONLY the professor could take that photo with that angle. （/TДT)/
Alright, so what does this means? Well we can guess professor wanted to end that realtionship for a different private reasons and he lied to him.. (fuck you)