"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!"
-Fred "Hey, Nohomobro."
2) A doctor is giving his patient a prostate exam, he says: "Nohomobro"
3)Your friend says a funny joke and you reply after laughing "I love you dude!" followed with a "Nohomobro."