“be curtains for sb”别理解成“为某人做窗帘”，其正确的含义是绝望的处境；无法摆脱的困境；完蛋。

【例句】
Unfortunately, if this merger doesn't go through, it's curtains for our company.
不幸的是，如果这次合并不成功，我们公司也就完蛋了。

If your work doesn't improve, it will be curtains for you.
如果你工作不改进，你就完蛋了。