<prompt> Human: My boyfriend and I are in the process of separating and disagree about how to split the house fairly. In July 2016, my boyfriend and I purchased a house together. Both of our names are on the deed.My boyfriend paid the entire down payment, with the understanding that I would pay the mortgage until we were even. Our cardinal sin was not defining what even meant. He paid a 30k down payment, and I have paid the full mortgage since July 2016 totaling approximately 20,000. If we sell today, we stand to make at least 50k on the house. He thinks that he should get his equitydown payment back in full, and then we split the appreciation equally. I think that he should get his 30k down payment back, and I should get the 20k Ive contributed. If there are additional profits, I propose they be split evenly between us. His reasoning: Its a time value of money problem. We dont become even when your monthly payments equal 30,000. I think the basic way to do it is figure out what kind of annuity I could have bought for that 30K and compare it to the payment stream of the mortgage My reasoning: In this instance, 30K equals 30K. Please help us decide how to do this fairly.  <response>: Our cardinal sin was not defining what even meant.The cardinal sin here was buying a house with someone you arent married too. I think in a relationship saying You pay the mortgage until we are even would simply imply you pay the mortgage until you hit the 30K mark, then youre square. Thats certainly what I would mean if I said that were I the guy in this situation. That he now wants his 30K back, plus 12 the equity, while essentially living rent free for 2 years is some bush league stuff. He gets his 30K, you get your 20K...then split the difference. 