The mother of one of Jerry Sandusky’s alleged child sex assault victims tells ABC News that her son felt he didn’t have the power to resist the former Penn State assistant football coach.

The boy also told his mother that he was so traumatized that he still has difficulty openly discussing what happened years later.

In fact, even the boy’s mother did not fully understand his allegations at first, she told ABC News’ George Stephanopoulos in an interview to air on “Good Morning America” Friday.

“I had said, ‘You know, maybe we should have come to this conclusion earlier, you should have told me,’” she said she told her son.

“He was like, ‘Well, I didn’t know what to do. I didn’t know what to do, and you just can’t tell Jerry no,’” she said.

Watch “Good Morning America” Friday for more of George Stephanopoulos’ exclusive interview with the mother of “victim number one.”