Ok tough situtation............. i need advice?

Ok i am a 28 year old mother of 4 children. I have been dating this guy for almost a year and once in a while he will stay the night at my house. I see nothing wrong with this per say, but my family takes a different perspective. He gets along wonderfully with all my children and helps us out whenever we need anything. My mother picks up my kids of a morning so i can get to work on time, and i appreciate everything she does for me, but she is also very controling. She doesn't really know the man i've been seeing that well but made the comment this morning that i was sending the wrong message to my children by letting him come over. She also threatened to quit helping me if i didn't stop seeing him. And then when i got mad and told her what i thought she threatened to call social services saying i was neglecting my children because i was even seeing someone. I need her right now and she is hanging that over my head. This has had me upset all day so any advice would be appreciated.