What to do about the house

We are not married. The house is in both of our names. I moved out the beginning of this month and I am still paying half the mortgage. He has since allowed his girlfriend to move in. Do I have any rights if I refuse to pay my portion of the mortgage since he has someone else living there? I have it documented where I told him I did not want to pay if someone else lived there. He refuses to refinance with her, he also said in writing he was not going to live there with her. Yet she has.

Do I have any rights in this matter. I dont feel its right for me to continue to pay for half the mortgage if she is living there. I have taken pictures as well.

Note the house is currently on the market…

Thanks.

You likely do not have any rights since your house is deeded to both you and your ex-boyfriend and you are not married to each other unless you and your ex-boyfriend signed a contract agreeing to the details regarding someone else living in the house, the mortgage being paid, etc. Furthermore, assuming the mortgage is in both of your names as well, if the full amount of the monthly mortgage payment is not paid in full, it will affect your credit as well.