
Okay, I know I've read a couple of stories like that but I'm drawing a blank! Here is one to where two guys are in love with a man and woman who are getting married to eachother and they basically find themselves drawn to each other in the pain of the heartbreak.
https://www.mangago.zone/read-manga/secondo_piatto/

Side couple in this https://www.mangago.zone/read-manga/pochi_to_tama/

These two!!
https://www.mangago.zone/read-manga/crossline/ this is poly too iirc
https://www.mangago.zone/read-manga/love_debugging/ genuinely can't remember if it's poly but there's bickering for the same guy and good 3p

THIS ONE EXACTLY !! LIKED THE SAME GUY AND CONSTANTLY FIGHTINGG
https://www.mangago.zone/read-manga/nande_koigataki_ga_ki_ni_nannen/
Are there any manhwa/manga where 2 guys like the same guy. And they constantly fight but kiss somewhere along the story.