They would also blow our cover if we had to use them.
For one bad moment, he thought their cover had been blown.
Told him his cover had been blown from the beginning.
It would only take one phone call to blow her cover.
His cover would have been blown for sure if that had happened, don't you think?
Guess he was either in on it or else got his cover blown.
Everything legal and above- board; no need to blow his cover.
That was all he could say without blowing his cover.
If this has blown my cover, you may not hear from me again.
I could blow her cover, but then what happens to my wife?
Idiome