The thing is until the anime started airing I (and even a fujoshi friend who reads manga) never considered the possibility of Yoshino x Mahiro pairing.
If I had to ship a BL pairing it would be Mahiro with another character, but definitely not Yoshino.
I blame the anime for those BL feels which prevent fanart with my pairings
I hardly see Yoshino x Aika fanart for example.