I recently started a new relationship with a girl (Es). We aren’t even dating yet but we have had the conversation that we are “exclusive” 

Before we became exclusive I had made out with a different girl (Lu) that ended up making out with my brother after. My brother and I had text each other that “he will have sex with her and I can have her after” and I agreed with it. That is honestly not the type of person I am. 

Es saw the messages between me and my brother and now she thinks I’m disgusting and I just treat women like a piece of meat. Idk how to verbalize that I’m not that type of person and that I was just talking shit with my brother.

Since becoming exclusive with Es I have formed great feelings for her and I can’t lose her. Idk how to prove to her that I’m not as disgusting as that text made me seem