An opportunity cock is the man who is not chosen by a girl when she has to make a choice between 2 guys. Deriving from the term opportunity cost, meaning the item not bought when choosing between 2, the opportunity cock is basically the man the girl leaves behind at the bar when she sees a much more attractive rich man.
John: “Can’t believe Ann chose Andrew over me. What’s wrong with me?”
a favorable juncture of circumstances when a person realizes the need to fart and can do so by relieving the need (farting) in a area occupied by other people and then vacating the scene.