curtains for, be.

curtains for, be.

Also, it's curtains. Be the end, especially death. For example, If he hadn't worn a bullet-proof vest, it would have been curtains for him, or It's curtains if she doesn't finish on time. This expression is a metaphor for the falling curtain signifying the end of a performance. [Slang; c. 1900]
See also: curtain