I also think it's fair that he should pay for some of the house or take care of it, if he wants a share in it. And, definitely have it written down on a legal document. You might not want to pay for a mediator, but you may find that you will get more done with one. More legally binding perhaps?
Me:57 H:52 M:28 Got another lawyer last year and filed. D35,S/D twins28,D22 EA4/04 End? Who knows? "Life is like a mirror. Smile at it and it smiles back at you." — Peace Pilgrim