Can I collect Social Security fro ex spouse?

We were married 15 years, raised 2 children. Been divorce 20 years. He is remarried, I never have. We will both be 62 in 5 years. I would like to retire then. No money to retire on as lay offs have emptied my retirement so I must depend on mine and possibly his social security. I will not be getting any of his retirement as it was not added to the divorce decree. What if I was to start receiving his social security when we retire and I was to remarry? Would I lose his social security?