No, that's not it. Noah was kidnapped and Jaechan saved him. To remember it properly, read this chapter again.
https://www.mangago.zone/read-manga/success_oriented_guide/uu/br_chapter-236818/pg-1/
Blondie is his (maybe still) homophobic roommate. He is like never in the room because he was scared of Jaechan’s cooties. But we know he was acting like that cause he had that middle age man stalking him. And Jaechan saved him. When he gave Jaechan guiding he is affected in what seems to be an aroused way which kinda confused him. So now he has a sorta crush on his roommate and maybe he now wants to be friends since Jaechan rescued him. Understandably so coming into his room and seeing another guy caressing the underwear of his roommate (assuming those are Jaechan’s and not his) after clearly having been choking him is going to stir up wtf get the fuck outta here vibes for him lol
im so sorry who the blond guy again? also the brother eww who the fuck would pick up their sibling's undies man disgusting