Offended By "Cat" ?

[Sigurd]

The two proverb/Idioms I think of regarding cats are:

1. Buy a cat in a sack
Meaning: You got conned. Might be from the middle ages where someone would sell you a cat, claiming it to be a piglet. "Can't open the sack you see, the squirming piglet might flee".

2. Let the cat out of the sack.
Clear reference to the first, but this time you disclose a secret or something that should not have been told. Or the tale you told can't be retrieved, "the damage is done" so to speak.