TnGuy...if you think by pitying your ex gf that means you don't hate her, then you are just confusing these two things. Your form of pitying her is to view her in discust. And holding someone in contempt and discust are basically the ingredients for hate.
This is normal and natural after someone hurts you.
However...if you think your feelings on this topic aren't clouded by what that girl did to you, then you are not very in touch with yourself.
Regardless, we are all entitled to our opinions and yours is VERY CLEAR. You hate cheaters - so okee dokee! Feel free to do so.
