1. Be careful. If you try to find out more than you should about her past, you might be opening Pandora’s box.
2. Larry thought the sale of his mother’s house was a Pandora’s box. There were too many people to please and too many people who might be offended.

Synonym: can of worms, open a. The expression originates from the Greek mythological character Pandora, who was given a box containing all the evils that could befall mankind. She opened it, unleashing all mankind’s ills.