How do I recoupe what I have spent on 'so called' partners house?

I am involved with a married man and have been for over 6 yrs. I left my husband for him and moved into a house (his) he remained at home with his family. He does not have a relationship with his wife, I know this for a fact, however he says he wanted to remain at home for the sake of his kids and as soon as they get to an age where they can handle it we can start our life. In my opinion they are now at that age and have been for some time but he still says they need longer (they are teenagers)....my family ( inc my kids) and friends can't understand why we are not living together, aprt from my very best friend no-one knows he is still living in the same family home as his wife, they have seperate bedrooms, and before you all jump on the band wagon and say 'oh yeah course they do', they really do I was his friend for 4 years beofre we got in a relationship and I knew his home cirstances, I used to say that is was quite sad for them both, he said that in a lot of Indian households it's the norm..if I had ever thought otherwise I wouldn't be sat here typing out this...anyway I have now made decision to move on and that he is a BIG FAT LIAR, but have spent ���'s on the house (it's in his name) and will be left with nothing, I would also find it hard to get a mortgage, (I am on the wrong side of 40) I am not looking to fleece him I just want some of the money I have spent on the house I thought was going to be our home BACK!! I doubt very much he will be of the same opinion..any ideas?