Carlos and I overheard you and Nick fighting...Something about blowing your cover.

我和卡洛斯无意中听到你和尼克吵架的内容，听到你们在四处躲藏。

Anytime you present false information and then you let the truth slip out, you have blown your cover.

任何时候你提供了虚假信息，之后你无意中说出了真相，你就泄底（blow your cover）了。