Hahaha, oh dear, I'm derailing the thread into my personal life ... try again:
Admittedly, she often leaves off the last 4 letters of that one, but it's clear when she says it she doesn't mean I'm stubborn

However, I made the point because it returns to some of the things that have been core points of this thread: I know when she says it, it is (nearly!) always lighthearted, and normally in a response to a tease. I could choose to take it insultingly and offensive, but I don't, because I have a fairly good idea how it is intended. It ties in very nicely with some of Kirby's points: she wouldn't say it if it was going to upset me, and I assume that she isn't trying to offend me, and this is all because we have taken the time and effort to get to know each other (good job really!)
She's not called me a scumbag yet - somehow, it's hard to make that sound endearing (I have no idea why the way she says a** is endearing, but it is).
Most offense I suspect is due to ignorance. Both on behalf of the communicator in not understanding the societal sensitivities he is communicating to, and on behalf of the communicated for not realising that the offense may be due to the offender not understanding. Sometimes assuming good faith can go a long way
