"Nohomobro" refers to the act of doing something that could be viewed as homosexual but in reality isn't or has no homosexual purpose behind it. As a result, the person doing the act simply says "Nohomobro" and the action is thus deemed "non-homosexual" when used reasonably.
1) Fred had to weigh in naked to make weight in wrestling and his friend Joe happened to be in the locker room
-Joe "Aww dude, that's gay!"
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi