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'.”
(..) ♪ The second time around. ♪ ♪ And you've... got... ♪ ♪ time...! ♪ ♪ And you've... got... ♪ ♪ time... ♪ So there's an entire pig in there. Yes. For four of us. It's a small pig. I really wanted to use the box. It was my birthday present. She's guilty she's leaving. It's a guilt pig roasting box. At least you get something. I'm not getting laid for a year too. But what do I get? A baby? You can't eat it. Are we really gonna eat that? (..)2013 TvShow: Orange Is the New Black Title: I Wasn't Ready Season: 1 Episode 1