He is a sexist 'pig'. = He is a 'male chauvinist pig'. [=he is a man who thinks women are not equal to men]
The train station will be renovated 'when pigs fly'. [=it will never be renovated]
“This time I think he'll ask me to marry him!” “Yeah, and 'pigs might fly'.”
(..) Look at them, they're always stinking of shit. We got horses over here. Alright, bridger. We got horses. What you wanna do about this pigs? Lord is on our side kid. You alright there kid? You're head in the right place? I guess. Can't help thinking about (..)2015 The Revenant