we are siamese if you please. we are siamese if you don't please

Tonight at the back-to-school BBQ my friend Kim came and sat by us. She has 1 year old twin boys. Gracie saw one of the boys and asked "Is he 1 year old?" I said "yes". Then she noticed the other twin and said, "How old is he?" I said, "He is one also. They are twins." Then pointing to my friend, Gracie said, "they where both in her tummy at the same time?" I said, "Yap". Then Gracie said "Soo, their heads were stuck together?" When I was done laughing I let her in on a little secret. Not all twins have their heads stuck together.