He leaves me out of all of important information for work. He talks about me behind my back as well.

He yelled at me a few weeks back because a report went through the system on my computer but not on his and he thought I was in the wrong.

ever since than he been a complete ass to me

Sad thing is - they say "oh well that just Brett..that how he is". And Im just a temp so they will believe him over me.

Corner him outside of work and tell him that he better start being nice to you or you will cut his nuts off.

Right...dont think so! He leaves before me anyways and he is high strung so it wouldnt be a good conversation with him