The Cooliest's manga / #Brother Complex(2)

Two friends and one's step-brother. One day, the older brother notices a bunch of girls admiring and shipping his step-brother and his best friend. He thinks that if anyone is to have his little brother, he's fine with it being his best friend but for some reason when they find them "kissing", he starts crying.

Guy who's super attractive but is actually a bro-con and his gay friend who has been in love with him ever since they were in university. Has a sequel.