Yep the ML is the older brother, the younger brother is a huge red flag and selfish as hell, he takes after his father.
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Does the og mc sleep with the younger brother?
Wdym by og MC?
The omega dude who was existing be4 the dude who dies at first possesses the Omega's body
Oh Il-seo, yeah he always had an affair with the brother, and the husband never really cared about it, not until Dong-sik came, so technically the husband loves Dong-sik not Il-seo. But in the side story Il-seo and the brother-in-law meets and the BIL actually got interested in Il-seo which is in Dong-sik's body. But there's no story if they actually got together, but it's heavily implied. The brother-in-law loves Il-seo not Dong-sik.
the mc will probably end with the older brother right?
I think the younger brother is better looking, but I am not crazy about his character...