something that you say before you say something that is unpleasant but true

Let's face it, we both know why I stopped working there. 实话实说吧，我们都清楚我为什么不在那里工作了。

Let's face it, we're not going to win.

said before stating something that is unpleasant but true

Let's face it, we're not going to win. 我们面对事实吧，我们不会赢的。