Why won't he commit to our family?

My partner of two years refuses to commit to me. He is 58 and I am 24 and we have a 15-month-old baby. We love each other, he gives me an allowance, pays for everything and takes us on holidays.

He bought me a car but put it in his name. The age gap makes absolutely no difference. I have repeatedly told him that I want marriage and another child but he doesn't want to marry.

When we argue he threatens to throw me out. I do not have a job and I have no reserves should the relationship fail. He has not made any provisions for our son or me. I do not want to lose him.