Is there a word or idiom to describe being offended for some one else?
For example, Person A makes an off-the-cuff remark that person B is 'trailer trash'. Person B knows that person A means it as a joke and isn't offended. Person C then gets offended at the remark and jumps to person B's defence even though the remark had nothing to do with them. Person A and B often make these remarks to each other.
Best Answer
I would suggest vicariously offended.
Vicarious:
I've found a few published uses of the phrase:
Use 1:
Use 2: