Ok it's probably a mind thing going on as you say you've got back with your old girlfriend whom you called a 'hag" and it's fine!?
Yet with the newer one who you deem hotter you have a problem? That would tend to indicate it is psychological.
I'm just not too sure about calling the old girlfriend a hag then getting back with her almost as a 'test' to see if things are ok?
People are people and you wouldn't like to be termed an ugly dude or the such. Be careful because as a previous poster said perhaps you don't think you deserve this new girlfriend?
Take Care and be good to the ladies, Sam