Don't hold your breath.
[Idiom] DON'T HOLD YOUR BREATH. - Managing Expectations: The Art of Patience
Don’t wait expectantly.
'Don't hold your breath' is used to inform someone not to wait expectantly for something because it might take a long time or never happen at all. This idiom serves as a caution against optimism in uncertain situations, tempering expectations by preparing someone for a possible disappointment or a lengthy wait.
Example Sentences
If you're expecting an apology from him, don't hold your breath.
Don’t expect an apology from him anytime soon.
They promised quicker internet speeds, but don't hold your breath waiting for it.
They promised faster internet speeds, but don’t expect it to happen soon.
She said she'd pay me back tomorrow, but knowing her track record, I won't hold my breath.
She said she'd repay the money soon, but given her history, I doubt it.
