If so, I'd recommend this one:
https://www.mangago.me/read-manga/nande_koigataki_ga_ki_ni_nannen/
But there is a twist!
I do know a poly story too, although at first MC does look at it as a love triangle:
https://www.mangago.me/read-manga/crossline/
As for a guilty pleasure of mine, it's really rare but I do love the very few stories that exist in the BL genre where the crazy, unstable one is the character who bottoms in the relationship, which subverts the trope of them being ultra-feminine and innocent/weak. I just love when the power dynamics are in the bottom's favor! I read too many crazy stories years ago featuring crazy top characters that left a very bad impression and made me want to see the opposite!
Well, there are very few stories I can think of where it's two characters who bottom fighting over a top, however the one I DO know is kind of insane/has red flag characters and dark themes (SA, blackmail, corruption, obsession, major plot twist), so I will earn you in case you'd like to skip on it. I will
If you'd still like to check it out:
https://www.mangago.me/read-manga/yokosu_inu_mekuru_yoru/
However I will say that this doesn't satisfy your earlier request because the MC is unfortunately the one/top being fought over by the two bottom characters.
Of course, if I come across any love triangles with two bottoms fighting over a top that is fluffy/has green flags, I'll return and put you on!
Honestly everyone hates on love triangles but I actually enjoy them, (I’d love to read one where the mc isn’t the center or the love triangle? But rather trying to win the love interest over? Idk how to explain and think it doesn’t even exist)