John is the boss and Joan is his assistant. 'Your telephone is off the hook and you always sit there knitting. You're fired. I'll be happy to see the back of you,' John said to Joan. In this case, he means he can't stand Joan any more and he'll be happy to see her leave.
'To See The Back of Someone' 意思是摆脱某人，看着他 / 她离去。'To See The Back of Something' 意思是摆脱了某事物。 所以当你想说很高兴摆脱了某人或某物的时候，你就可以说： I'm so happy to see the back of …
