I could only think of one manhwa ╥﹏╥
https://www.mangago.me/read-manga/love_remedy_1/
(Mc is obsessed with d. Can't blame him with these guys around him lol)
(Multiple people with the MC)
https://www.mangago.me/read-manga/a_man_who_gives_it_all/
https://www.mangago.me/read-manga/now_open_door/
https://www.mangago.me/read-manga/wet_sand/
https://www.mangago.me/read-manga/three_nights_we_really_do_it/
(Sorta)
https://www.mangago.me/read-manga/swallow_you_whole/
(Multiple people with the ML)
https://www.mangago.me/read-manga/the_boundary_of_delusion/
Here you go darling, I got a BL harem list of you’d like to check it out! (≧∀≦) I hope you have fun!~
https://www.mangago.me/home/mangalist/2692935/

Does anybody know any BL where multiple people are interested in the ML? Doesn’t matter who he ends up with :)