Most Helpful Guy
What makes girls treat a guy like shirt in a relationships?
Both genders are nasty creatures... not just men.
Most Helpful Girl
I'd say for the most part it has to do with the guy more than the person they're with. If you're a good guy, you won't treat your girlfriend like crap.
However, girls can contribute to this in a way by what they put up with. A pattern of allowing abusive behavior or to be walked all over will make you more susceptible to guys like that.