I've met this phrase in a manga translation.
Let's suppose there are two characters - Bill (male) and Jane (female). An accidental kiss happened between them yesterday. Bill didn't consider it as something worth paying attention to, while Jane was the opposite.
On the next day, when Bill asked Jane about some important matter, she was still spacing out because of this kiss, so Bill said:
"Why are you so self-conscious over that for?"
I understand when a sentence ends with a preposition like "This is not the thing I can put up with.", but there I can't think of a verb that has this for.
My point is - I understand that this for gives some additional flavor to this sentence, but I don't understand the grammatical side of things.
Could anybody explain it, please?