He said he'd finish the project by Friday, but that'll only happen when pigs fly
She promised to apologize, but I won't hold my breath; that'll be when pigs fly
You think he'll share his profits? That'll be when pigs fly!
I'll believe he's on time for once when pigs fly
She claims she'll win the lottery next week, but that's a scenario that will occur when pigs fly
He'll clean his room if you ask him nicely, but that's a fantasy that will materialize when pigs fly
The politician will actually listen to the voters when pigs fly
We're expecting a rational debate, which, given the participants, is likely to happen when pigs fly
He said he'd call me every day, but I know that's a promise that will be fulfilled when pigs fly
They'll ever agree on a solution when pigs fly
Will you finish the project today?
I will finish it when pigs fly.
So, never then, I suppose.
He'll pay you back when pigs fly
He will never pay you back
That's never going to happen