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'.”
(..) It's time for new blood in the North. If you acquire a reputation as a mad dog, you'll be treated as a mad dog. Taken out back and slaughtered for pig feed. Maester: A boy. Red-cheeked and healthy. My congratulations, Lord Bolton. (..)2016 TvShow: Game of Thrones Title: Home Season: 6 Episode 2