✔ Can of worms
If you say a situation or an issue is a can of worms, you think that getting involved in it could lead to problems.
■ For example:
- Corruption in politics is such a can of worms that many journalists won’t take the risk of seriously investigating it.
- Cathy never talks about her childhood. She says it’s a can of worms she doesn’t want to open, though I have no idea why.