Kitto Kiss wo Suru Toki

Shin adores his little brother Satoru and childhood friend Mitsuya, but starts having strange feelings when he overhears a couple of fujoshi talking about how hot it would be seeing Satoru and Mitsuya kiss. He thinks he'd be happy accepting a relationship between his little brother and best friend but when he walks in on them actually kissing... he starts to cry? (Source: MU)