DP asked me to move in with him. I moved in at the beginning of July and since then, my flat has been on the market with no luck selling it so far. He hasn't demanded any money from me yet as I am still covering a mortgage. I thought the agreement was that when my flat had sold, we would split the mortgage/bills down the middle. I am happy to 'rent' off him and not get anything in return when he sells his flat. However he has made a few comments about when my flat is sold and I 'backdate' him the money I 'owe'. I understand I have lived there and am more than happy to contribute to bills etc and I do most of the cooking etc but backdating me rent when I have still been paying for a mortgage seems a little tight to me! I have brought the subject up with him and his response is that I have been living there so I should pay.