I think the issues are : if reviewing from their second meeting as well(chapters 1 and 3) and combined with their first meeting(this flashback, ch 40-44) when Colton was angry because jinwoo attacked minjae(when they had s**, Colton said in ch 1) "the mere sight of an omega makes you lose control). There, Jinwoo questioned himself about Colton's said in ch 1 "why did he act like that?"(angry about he attacked minjae), maybe Colton loves minjae or Colton let himself fall for pathetic omega" so now he has the answer, actually he's aware from the start when he meets with Dylan but he still not sure and still dig the truth. Now because he remembered their first meeting with Colton about full of resentment of him when they had s**, he's sure about that which is Colton had always wanted to love Dylan(omega) but something was hindered. This also make sense considering at the beginning of the chapter Colton was very annoyed with him and always listened to what Dylan's need also give Dylan affection. So about Colton suddenly likes him and told him about their relationship to be serious is something strange to him, even though he likes Colton for sure. From the last point of view, Jinwoo didn't know Colton's point of view, who was no longer thinking about Dylan but thinking of him. Especially when Jinwoo saw Dylan on the phone with Colton around ch 26, Colton was felt angry (jinwoo thought Colton was disturbed because of Dylan's need) so it was natural for jinwoo to judge that Colton is still concerned about Dylan's needs. They just need to communicate this problem, if jinwoo would know the truth soon about ties up with Dylan everything would safe(maybe still need little time to process Colton's words to him). (1)
