To be Honest, At First hyung joo Is an Asshole, He's just a prick of a delinquents.
We Thought Of Hyunwoo is The Good Guy but after seeing how he's also a bit Dull and Weird sometimes when in love state, Also Once Hyun joo Realised his attraction to Itlak We can see how Sincere and Considerate he can be despite his Assholelistic Demeanor.
I believe Hyunjoo Right now Is Letting Itlak Be with Hyunwoo Because joo is Still In A Great Regret for Bringing Itlak to a Very Dangerous Situation with the 3rd year.
He realised he had done worse to him and so he probably backs away. I dont know but we'll see
(I really wished there'll be a Sex or at least NSFW scene)