I think he's not a homophobe, he just have a status of a scholar that he need to uphold, so he's afraid that something scandalous and taboo as liking a man would tarnish his image. So basically he's a closeted gay asshole.
And yes, I also think that he likes nakyum, that's why he had that expression on his face.
I remember somewhere along the chapter that Nakyum had a poem written to him, though Nakyum doesn't know how to read but he treasures the poem so much because it was given to him by that beloved teacher. The Lord confronted the Teacher when they was hunting in the woods before, by sarcastically remark that how ironic that the Teacher doesn't want nakyum to draw porns but at the same time he dared to wrote and gave nakyum a lewd poem.
No, I don't think it's about hating gays for the teacher. It's about finding any reason to look down on others. He looks down on the Painter because the Painter paints erotica, is illiterate, and lowborn. He looks down on Yoon because Yoon is a sodomite and lewd. He just shops for whatever reason he can find to say "I'm better than everyone".
The poem was never lewd, it was just a bad attempt of plagiarism(Yoon reads it in chap 4). Nakyum seems to know how to read, but he's still an ignorant, so he doesn't notice the plagiarism. That's what the Lord was referring to in chap 22. :3
But I believe there is a tiny possibility that Inhun might be a closeted gay. If you reread chap 21, you'll notice that there is a panel focusing on one of Inhun's book, which has a paper in middle of it. Perhaps, its that painting he discovered when he scolded Nakyum.
Well, to be fair, we, the reader have an omniscient viewpoint. We get to see shady teacher for who he really is. The Painter only has what the shady teacher has shown him. He grew up around the teacher who was probably like a father figure or older brother figure to him. The Painter was raised in a brothel and probably in desperate need of a father figure and there was the painter.
I think his love for the teacher is a mix of romantic, admiration, and longing for a safe big brother figure.
First chapter.
Okay. Does the teacher hates gays so that’s why he has that kind of face when he asks the painter if he’s had sex with him, or is it that the teacher likes him too? I’m in confusion