Jerry Sandusky's Son's Oprah Interview -- Matthew Sandusky Details Sexual Abuse

Jerry Sandusky's adopted son is finally going public about the years of sexual abuse he suffered at the hands of the former Penn State Football coach ... in an emotional interview with Oprah.

Matthew Sandusky sat down with Winfrey for a special for OWN that will air on July 17th -- and according to the network, he will reveal "never-before-heard details of the sexual abuse he experienced as a child at the hands of his adopted father, and why he is choosing to speak out now."

Matthew says the abuse started when he was just 10-years-old ... and at first, he thought he was the only victim.

Matthew also told Oprah, "At bedtime, his ritual began."