I am not talking about flawed, evil or manupulative protagonist. It should be antagonist of the story regardless of their characterisation being good, evil or grey. Also girl doesn't need to be fl, any female characters will do.

The closest eg would be so "I married an antifan" or  "kiss goblin" (though it was bit ambiguous)

Maybe The Romance of Hua Rong Season 2? The SML starts as the antagonist who wants the FL for himself but he ultimately ends up siding with the leads and has a love interest of his own by the end.

Also possibly Night of Love With You (ML is the antagonist of the story because it's set within a manga and he ends up with the FL in the end).

 adampk:
I am not talking about flawed, evil or manupulative protagonist. It should be antagonist of the story regardless of their characterisation being good, evil or grey. Also girl doesn't need to be fl, any female characters will do.
  • IMO, My Dearest doesn't have one consistent antagonist. There are several characters that take on antagonistic roles at times, including General Yong Gol-Dae, Princess Gak Hwa, Royal Concubine Jo, King In Jo, Officer Gu Won Moo, and scholar / official Nam Yeon Jun. Gu Won Moo and Nam Yeon Jun were both secondary male characters who were love interests for the female lead at certain points, and they both ended up being married to other women. At times they both seemed kind of alright, but in the end I loathed both of them
  • In The Princess's Man, the FL's father is the main antagonist. It's been a very long time since I've rewatched it, but iirc correctly he is still married at the end of the drama
  • In KinnPorsche, Vegas was one of the main antagonists. I wasn't a huge Vegas x Pete fan, but iirc they were together at the end of the drama. They might even have gotten a spin-off? Someone else can hopefully confirm. This one is a BL.