Is it omegaverse? Maybe Dog and Bird?
Not omegaverse, it is a manga by the way, they were bros and I think his friend was in love with him for some time and he was oblivious so in the first chapter when he suddenly gets kissed during the threesome he is like "?" But I can't remember anything else TT
Hehe I think i can help ahhh sorry I'm so happy cause I was in your position like a month ago it had been eating me alive so longg hopefully it is the one you're looking for
https://www.mangago.me/read-manga/ryuuku_ai_utsu/
OMG YEAH THATS IT THANK YOU (づ￣ ³￣)づ
YYAYYY genuinely so happy to help lol
Someone please tell me the name of this one, it's been in my mind for a while and I can only remember that they were friends, both very straight and popular, so at the start of the story they were fucking the same girl and suddenly his friend kissed him or something (?) or maybe his bro put it on him but I'm not sure, I think it was a kiss. So yeah, that's all. (￣∇￣")