Can I sue for a broken agreement?

My wealthy ex boyfriend of many years promised to buy me a house on a few occasions. A few months ago, he made the promise again as an effort to be my friend since I had not talked to him in a month. Almost a month later, I find that he is engaged to another woman and had been for years. I left him alone. He called and asked if I would be his friend and in return he would buy me a house. He also sent text messages to make the deal. If he changes his mind, would I have a case?