whats the origin of the phrase "work my bum off"?

Answer 1

That's a toughie. Actually the correct phrase is "Work my buns off." I suppose it's a more polite way of saying work my A**off. I couldn't find any information on its origin but my guess is that it is probably English in origin. I guess whatever people refer to one's rear end as buns would probably the same people who made up this idiom. If I find anything further, I'll come back and edit my info.

Answer 2

Dunno but i'll bet its Aussie in origin!