When someone is interfering with something you are doing (could be while working or not ), always there being annoying, bothering or critizing you...aaghhhh... just shows up to nag with non-stopping blah blaaaaaaaaaaaah blaaaaaaah and it seems he doesn't understand the non-rude ways you have to say that he has to stop, you can always use the not very kind (but sometimes very necessary) "GET OFF MY BACK !!" (feel free to add more "pretty" adjectives if the case requires it ... ^^ ) ;)

Get off my back It generally means that : stop interfering or stop nudging someone in his work or anything similar. I am not sure about its origin but if you know then please let me know. Leave me alone!; Stop following me!; Stop dogging me! (Usually objectionable.) : Stop pestering me! you can also say : Get off my tail! Get off my back! Example : 1- I was unable to finish my project because of my friend’s interference hence I asked him to “get of my back”. 2- Get off my back! Go bug somebody else. http://hiss.in/25/get-off-my-back-idiommeaning-n-definition/

If someone is annoying you constantly then he is getting on your back. It feels like hi is sitting on your back and you want to get rid of him. He could just be watching you, like an ever present boss. When you don't want him to be around any more you tell him to get off your back.

"Stop bothering me", "stop nagging", etc. Imagine someone shouting at you from behind, telling you how do to everything, or hanging over your shoulder with complaints about everything.

"Get off my back"= leave me alone, go away.