Jack Shit Off - To take something and make it look like it was always yours,

To take something and make it look like it was always yours, even when it wasn’t

I copied your essay and got an A. You’re a jack shit off.

You did the work, but I took it and made it mine. You’re a jack shit off.

Your idea was mine, but I made it look like it was yours. You’re a jack shit off.