I’m gonna throw this one at you despite it being an ongoing manga and not a manwha
https://www.mangago.me/read-manga/yatara_yarashii_fukami_kun/
(they both struggle with love and its concept and it’s explained later why for quite valid understandable reasons that I’m not spoiling)
to summarize: mc (who starts off as a light yellow flag at best) works in an office where he’s popular and admired by his co workers who all have no idea he’s actually a narcissist playboy
outside of work he’s hooking up with guys and on dating apps but to his own dismay cannot find love (while judging and rating his own hookup and people lmao)
atleast until he meets ml who’s a fellow co worker but also his polar opposite that mc pretty much looks down upon at first due to his appearance and overall attitude until they go on a business trip that results in them sleeping together and making a deal that they’ll keeping sleeping together as long as mc doesn’t fall romantically for ml
yes there’s an 8 short episode anime adaptation that pretty much just leads up to chapter 24 I believe from the manga but with minor changes while still including the original sex scenes so it’s up to you if you wanna watch uncensored version with the dub which imo is better then the sub
there’s also the japanese live action adaptation drama that came out recently that’s actually pretty loyal to the original source material so if you’re into that sort of thing check it out as well

guys recommend other manhwa's with a similar dynamics with the characters i cant stop thinking about juheon and dohu skdjjd