My boyfriends mom doesnt want him to grow up?

Okay so my boyfriends mom is a very manipulative woman.She always wants things to go her way. Her husband is sick and she doesn't work.He gives her like 600 $ a month and doesn't even live there. She is a hoarder and spends money like crazy. She refuses to work because she is starting this ministry. My boyfriend and I have been best friends for 8 years and about a 1 1/2 years ago we started dating. He moved in and everything was great. We are happy our families were happy it was all wonderful. Well we have been talking about buying a house because I have a 4 year old and we are in an apartment. Well he tells his mom and she says well why would you want to house payments and he says we would only have one. And then she says well what about mine. Then every time we see her which is like 2-3 times a week she says oh you are never home you never come see me BLAH BLAH BLAH. He doesn't live with them and we see them very often. Well we were at dinner last night and his mom was basically trying to auction him off to this waitress and was telling her about his life story and I was sitting right there. The she goes on for 5 Min's after he tells her she is being rude and disrespectful that he is a hypocrite and he never goes to see her and he says mom im trying to live my life. This is an on going issue and im worried it is going to ruin out relationship. I don't know what to do please help