Wait I'm confused. What did Hyesung mean when he said Dojin brought another omega to the place? I can't remember what happened in the main story because I hated it
He brought a omega back when he and hyesung weren’t in any relationship yet.
Since he hated sleeping with an omega it confused him why he was able to and even liked sleeping with Hye-sung(they had a mistake? Sex cause hyesung went heat)
So he brought an omega to see if he liked the sex with hyesung because he is an omega or he just like it cause he like hye-sung
In the end he didn’t finish with the omega and went to hyesung’s room instead
Hope y'all remember that the reason why Heegyeom is in that situation with loan sharks is because of Jaehan in the first place.