I my-self surf the net for 5(mins) and got all these meanings of back off:
- Back off (no object): not follow a threat.
“Tom was ready to call the police when I told him I’d wrecked his car, but he backed off when I said I’d pay for the damages.”
- Back off: Retreat
The police told the protesters to BACK OFF.
BACK OFF: to retreat; not follow a threat
That car was following me closely, but finally it backed off.
to move backwards away from someone or something, usually because you are afraid
I saw his knife and backed off.
(slightly informal) to stop being involved in a situation, especially in order to allow other people to deal with it themselves
Just back off and let us do this on our own, will you? [often an order]
I thought I’d better back off and leave her to make her mind up.
(mainly American) to stop supporting something that you used to support, or to not continue with a plan
The president seems to have backed off from his ‘no new taxes’ promise. [usually + from]
(From Cambridge International Dictionary of Phrasal Verbs)
So upon my knowledge, I think you can use it in both situations someone mocks you and when you are cool with everybody. The evaluation is left for our moderators and correct me if I am wrong.