Definition
Used to advise someone not to expect something to happen soon or at all, suggesting it is unlikely to occur.
别期望了
They said they might promote me, but don't hold your breath.
他们说可能会提拔我，但别抱太大期望。
He promised to help, but don't hold your breath waiting for it.
他答应要帮忙，但别指望他会做到。
She said she would consider the proposal, but don't hold your breath.
她说会考虑这个提案，但别抱太大希望。