I don't think everyone of them is red flag
Having a fwb is common thing if two people have same intention with eachother, other then that twink i don't think ml and mc are red flag. The blonde guy was just not aware of his feelings and through the chapter we can see improvement alot. Idk why the blonde guy is getting hate he actually love the black hair guy.
??? are we not reading the same thing??? nanjo thought mokyeon was abusing seohwa so he wanted him to stay away. mokyeon instead of correcting nanjo decided to have fun, be a POS and deceive nanjo into a sex contract. mokyeon broke his end of the deal by giving seonhwa a hanjob, oral or sex idk. he's also not ending the deal now because bro caught feelings lmao. he deserves whatever is coming for him when nanjo finds out seonhwa isnt so innocent and mokyeon deceived him.
nanjo while isnt much of a red flag more like an in between. he could have asked seonhwa first instead of assuming things. bro is rich and powerful if he really wanted to keep seonhwa safe from mokyeon then there's a dozen other things he could do other than entering into a sex contract with mokyeon. why i thought of him as a red flag is because of how he is with his relationship.
honestly, all three of them are red flags. i hope no one ever encounters people like this in their life. seonhwa and mokyeon doesnt need to be explained. nanjo in a normal relationship, time together with your lover is more important than giving them expensive things.
i want nanjo to take off those seonhwa tinted glasses he has on and leave both of them. what kind of bad karma did he encounter from his past life to have those two get hooked on him