Old Sun finished using the bathroom, and his zipper was not zipped up when he came out.

He bumped into a female colleague at the sink; she finished washing her hands, looked up at the mirror, then lowered her head to dry her hands, without saying anything.
Old Sun felt something was wrong and looked down; his zipper was open.
He quickly zipped it up and awkwardly said, "Did you see that?"
The female colleague said, "See what?"
Old Sun said, "It's just... that..."
The female colleague said, "I didn't see anything, I am nearsighted and not wearing glasses."