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'.”
(..) What you reading, jackass and The rice stalk? That?s right, you keep walking. Look at me when I am talking to you. -Fucking slopes everywhere you look, man. Fucking pigs Look at that, man. That's my little cousin, over there. - You sure that's your cousin, man? Fuck yes, that's my little cousin. (..)2008 Gran Torino