Help please!

Okay so, my best friend and I got into a huge argument over his girlfriend because she is a horrible person and in my anger I told him that if he wanted to ruin everything over her I would go out with the guy he hated most (not really sure what I thought I would accomplish but I was really mad). So I added this guy and we started talking and at first my intensions weren’t right but the more I talked to him, idk I think I’m starting to like him but I know he’s not the dating type and my best friend would be so mad if I did anything with this guy... oh and on a side not we have slept together.. I’m bot sure if that changes anything. I’m sorry if this seems like a Rant I just really don’t know what to do