let something slip through one's fingers错过机会，痛失良机

【例句】
You can’t be more stupid! How could you let such a golden opportunity to make big money slip through your fingers? It was an opportunity that comes once in a blue moon.
你真蠢！这样一个发大财的机会千载难逢，你怎能痛失良机？

Don’t let a chance like that slip through your fingers!
别错失这么一个机会！