From The 'Rerun' Department Of "Say-What?"

Boy. Talk about butchering a perfectly good expression.

A certain 42 year old woman I know who shall remain nameless was trying to get out the thought that a colleague of mine was driving around not knowing exactly where he was going and did not exactly have a plan on where to go.

Only what came out was exactly, word for word, the following:
"This is like the fly of his pants."

To which I could only ask the question:
"Did you mean to say that 'he's flying by the seat of his pants'?"

After the laughter stopped, I think I was able to determine the answer was the affirmative.