Kinda, but he ran away because he was indirectly involved in something bad that happened to the seme (Aaron) and also he has commitment issues lol. He think his life would be better off without him
His mother died and the father never got over it and blame him for it. the father had threatened to kill his lover because of that he wants to stay away from Aaron
The reason Yujin ran away is because of the guilt and fear that his father would harm Aaron and would make Yujin as his pawn. After the Christmas tree incident, Yujin's mom lost her cognitive function and mistook Aaron as her son and she ran out into traffic and got run over which affected Yujin's dad so such (he is devoted to her) that he decided to abandon Yujin and kill Aaron and he did it almost and so it starts to weigh down on Yujin's conscience. After that car accident, Yujin was planning to leave to ensure Aaron doesnt get hurt, but for a while things went smoothly and Yujin reconsiders staying with Aaron but after that news report, Yujin went into mental breakdown thinking that it would harm Aaron and is blaming himself for Aaron getting hurt by his dad. Aaron knows this but he does not blame Yujin for it and begs him to stay by his side. But the guilt and pain ate away at Yujin and so he runs away
I dont think it's going to be complete bed of roses but also not complete pain. Yujin is still in love with Aaron and so is Aaron in love with Yujin. I think what's gonna happen is Aaron might mistake the situation and will knock out the guys and then ensues a fight and them forceful session before Yujin conks out due to his fever and then Yujin gets locked up in the house. Yujin may fight with Aaron to let him go so that Aaron wont get hurt and both fight and talk things through and then Aaron would deal with the father situation as well as media leaks. It's going to be complete misunderstanding turned angst and possible confinement trope
And as for Aaron, he is slightly psychopathic and can be bit of a red flag but Yujin doesnt mind it. Infact he likes his psychopathic tendencies. However Aaron does act nicely towards Yujin and treats him well but I think Yujin knows what is he getting into.
Initially Yujin is wary of Aaron and they are mostly in it for hookup in exchange for music but somewhere along the way, Aaron is starting to realize his feelings for Yujin and him being raised in a cold household, Yujin felt like a space where he can express his tendencies and Yujin feeling lost found Aaron tolerable and later on, starts to like him. To him Aaron feels like a burning sun which will guide him from his guilt, his pain from the childhood where his father blamed him and beat him up for an accident which is not Yujin's fault. Aaron brought a type of warmth Yujin craves and as for sex, well Yujin is pretty into intense stuff Aaron is engaging so the power dynamic to me seems Dom/Sub where Yujin is willingly letting Aaron overpower him.
may i know why did the bottom disappear? is top a red flag?