1. Joseph couldn't control himself anymore in front of all of his attendants. He cried out, "Have everyone leave me!" So there wasn't anyone with Joseph when he told his brothers who he was.
2. He sobbed so loudly that the Egyptians heard him. Everyone in Pharaoh's house heard about it.
3. Joseph said to his brothers, "I am Joseph! Is my father still alive?" But his brothers weren't able to answer him. They were too afraid of him.