Well if you go back to chapter 40. Hangyum explained everything but why he had been pretending (which He overheard Hajin) and why he dated Juri. And it is explained to Hajin off screen in 51. Hajin had his sister and Jaehee fill him in. Hangyum had his brother to guide him. In chapter 50 there is an indirect communication going on. (Saying something in between the lines). Hajin is saying things indirectly and Hangyum understands. It is an Korean story taking place in Korean they resolved it in different ways both resolve most themselves by the fight that happened in 40 and what happened after.
My friend explains it like direct communication “turn on the heater”. Indirect communication as “ it is cold isn’t.”
She said. Chapter 50 is titled is rekindled, Korean version had no title. The English translatiors picked up on it. (Even though they switched the dialogue.). Hajin makes a comment that what’s it to him and they broke up. Then after the kiss he makes another comment about not kissing someone who isn’t his boyfriend. He is indirectly communicating his desire to Hangyum. Hangyum picks up on it but it went to the wrong head. To Hangyum he answered Hajin and accepted but going a different path than Hajin meant at that time. Hangyum should had verify it after that kiss and the second comment from Hajin and before having sex. Lol Hajin just verify it after.
She also said a few lines was changed from the Korean one.
this manhwa was so unnecessarily complicated. they put wayy to much drama in the plot without fully explaining and resolving it.