I think we have the same exact tastes lmao
I have a list https://www.mangago.me/home/mangalist/2923299/ but the ones that fit your request the most are probably:
https://www.mangago.me/read-manga/work_fight_and_love/
https://www.mangago.me/read-manga/secret_alliance/
https://www.mangago.me/read-manga/master_s_pet/
https://www.mangago.me/read-manga/wild_city/
https://www.mangago.me/read-manga/undercover_chaebol_high_school/
https://www.mangago.me/read-manga/philia_rose_the_prophecy_of_the_crown_of_thorns/
https://www.mangago.me/read-manga/crimson_karma/ (here more than mc liking the first male lead it's that he seemed to be the established love interest from the readers' perspective)
https://www.mangago.me/read-manga/hate_mate/
https://www.mangago.me/read-manga/do_you_need_salvation/ (the 2nd ml in this adaptation was literally originally the male lead in the novel, but they listened to the readers and changed the endgame to the og!2nd ml LMAO)
https://www.mangago.me/read-manga/golden_light_gratia_the_child_loved_by_god/
is there any straight/bl/gl where the mc picks the second love interest? but not in a way that the first love interest only showed up for like two three chapters and it becomes very obvious they are not the final pick. i want a story where the mc genuinely likes the first love interest but slowly after time realise they are not the one and the second love interest is like it should be almost like a plot twist to us as viewers.