A situation whereby a male who is sexually inclined towards other males mistakes another male as being homosexual, and thus proceeds to attempt to win his heart.
Trent: Hey there big boy, I hear they call you Fat Tony... ;)
Ant: I'm not gay
Trent: I'm so sorry, I could have sworn that you ride the man train.
Ant: That's alright, just an innocent case of homoerrata...