Retaliatory Ex

A year ago I moved into my first home. Without much thought I had stuck my now ex's name on the title after he said he would not live with me unless his name was on the house as well. 3 months after he moved in, I broke it off with him and he moved out. Since then, I have been living in the house by myself. I put the house up for sale a few months later and well, unfortunately it is still on the market. The ex has now hired an attorney to assure that he gets half of the equity in the house when he has not put anything towards the house and barely lived in it. Can I file a Quiet Title to get his name off the deed since he can't show interest in the property since he has not lived in it? Even if he did pay part of the mortgage?