
I honestly think it would be for the best if neither of the three guys in this story got romantically involved with each other.
The high schooler is simply too young and inexperienced in life; right now, he's infatuated with the old man because the guy appeared in a fairy-tale like manner, a knight in shining armour who happens to save him from a nasty guy at the right moment. Combined with his stylish appeal and aura, it's no wonder the young guy fell for him instantly - but is it really love?
In regards to the teacher, he is just such a great, warm-hearted guy; too great for both of them, in my opinion. In a few years, provided the young guy manages to develop into a mature young man, he might just be able to make things work out with the teacher. But as of now, they seem to be perfectly fine in a student-mentor-kind of relationship.
Lastly, I feel like the old man has been through too much that the two younger guys simply cannot relate to. He needs a partner with life experience that can, so to say, "compete with" that of his own; someone of his age - at least mentally and perhaps physically as well.

YES!! I was weary of continuing to read because any of them getting together made me uncomfortable.
And it had nothing to do with same sex couples (I wouldn't have started reading this if it was) and not even the age gap as much as it was their different experiences and perspectives. Even towards the beginning when teacher found out about Father in law and they were talking about love and the father was telling him his rosy views didn't happen as often with the gay community already showed how different their views were based on their life experiences.

... If the author didn't include the adorable intimate hug between our two main babies, I wouldn't have made it through this chapter!
Byung should honestly just be behind bars so he can't hurt anyone; someone should confine and reeducate that crazy bastard provided he isn't a lost cause already! He seriously has no morals, no empathy and is, by no means, in a condition that would deem him capable of being in a relationship with a normal person. ╥﹏╥
... that JEALOUS JERK who, deliberately, ruined "teacher" and "cutie with black hair" 's date... I find him so obnoxious that I find it hard to read; if that prick ends up with the guy with the black hair, I'm gonna scream so loudly my neighbours will be deaf by the time I've managed to vent out all of my frustrations - provided my voice won't be gone by then. Everything that guy does ticks me off... ⁄(⁄ ⁄·⁄ω⁄·⁄ ⁄)⁄
Anyway, I really hope the cool teacher-dude who's an amazing cook X the soju-loving, black-haired cutie-patootie will be endgame; they are so adorable together and they're slowly falling in love with each other - I CAN FEEL IT! (๑•ㅂ•)و✧
Agreed (๑•ㅂ•)و✧