Not sure if these fit all criterias, though.
Completed:
https://www.mangago.zone/read-manga/sora_haena/ (GL manhwa; high school setting; smut in side stories; MC and FL have sex only when they are in an established relationship; side stories chaptered 1.-4. feature an age-gap, former student x teacher side couple)
https://www.mangago.zone/read-manga/sadistic_beauty_side_story/ (GL manhwa; college setting; passionate smut; BDSM)
https://www.mangago.zone/read-manga/opium/ (GL manhwa; historical setting - 1946. Korea; passionate smut; psychological, drugs)
https://www.mangago.zone/read-manga/on_a_leash/ (GL manhwa; enemies to lovers; passionate smut; violence)
https://www.mangago.zone/read-manga/serenade_keum_kyesoo/ (GL manhwa; college setting; MC and FL have sex only when they are in an established relationship; age-gap, teacher x student relationship; psychological, psycho side character)
https://www.mangago.zone/read-manga/the_playgirl_and_the_prince/ (GL manhwa; historical setting; passionate smut)
https://www.mangago.zone/read-manga/program_me/ (GL manhwa; office setting; passionate smut; boss-subordinate relationship, BDSM)
https://www.mangago.zone/read-manga/marie_and_alex/ (GL manhwa; historical setting; passionate smut; master-servant relationship, BDSM?)
https://www.mangago.zone/read-manga/addictive_bing_zi/ (GL manhwa?; passionate smut; BDSM)
Ongoing:
https://www.mangago.zone/read-manga/asumi_chan_is_interested_in_lesbian_brothels/ (GL manga; college setting; passionate smut; MC uses a lesbian brothel's services, no clear romantic relationship so far)
https://www.mangago.zone/read-manga/all_s_nice/ (GL manhwa; college setting; passionate smut; dub-con)
https://www.mangago.zone/read-manga/beast_of_blue_obsidian/ (GL manhwa?; fantasy setting; passionate smut; age-gap, master-servant relationship, non-con, dub-con, violence, mild gore, depictions of sexual assault)
https://www.mangago.zone/read-manga/love_thy_neighbor_2/ (GL manhwa; college setting; passionate smut; adultery, toxic relationship, dub-con)
https://www.mangago.zone/read-manga/amasaya/ (GL manga; high school setting; MC and FL are in an established relationship; no explicit smut but it is pretty ecchi)
https://www.mangago.zone/read-manga/drunken_my_boss/ (GL manhwa; passionate smut; boss-subordinate relationship, dub-con)
https://www.mangago.zone/read-manga/other_than_my_friend_s_sister_something_else/ (GL manhwa; love triangle; passionate smut)
https://www.mangago.zone/read-manga/lady_black_is_depressed/ (GL manhwa; historical setting; love triangle; passionate smut; master-servant relationship, non-con in chapters 14&15)
Thank you so much!! I’ve read a bunch of these but I do see some titles I haven’t read, so i’ll be checking them out
does anyone have a good smut recommendation where the scenes are actually passionate and it’s nicely built up to, characters have a connection ?(anything but BL, preferably GL)