Tim McGraw secret son: Revelation Faith Hill didn't even know about?

Tim McGraw has a secret son and his wife, Faith Hill, didn't know anything about it, according to a new report released March 6 by the Enquirer via RadarOnline. A source spoke with the tabloid and revealed that the country singer has stayed in contact with the son of his former girlfriend -- Kristine Donahue.

“When they got married, Tim promised Faith that he would never lie to her, and he doesn’t,” said the source. “But he doesn’t tell her everything. He keeps some secrets to keep the peace.”

The sneak peek article doesn't go into detail about when Hill found out about her husband's son, but she recently learned about him.

McGraw's "secret son" isn't biologically his, but he helped raise Tyler Zarbo when he was younger and never stopped communicating with him. Zarbo is now a 23-year-old student in Orlando.

"Tim McGraw was like a father to me when I was growing up,” told the Enquirer.

According to the report, Zarbo was like McGraw's own son.

“He saw me as the son he never had, and we’ve stayed in contact," Zarbo said. "I wish he could have remained as my substitute dad, but it just wasn’t meant to be.”

Is it true Faith Hill didn't know about Tim McGraw's "secret son" or is it an over-exaggeration that she was totally in the dark?

UPDATE:

Tim McGraw's rep -- Mary Hilliard Harrington -- issued the following statement to People magazine Wednesday:

"The National Enquirer story is full of inaccuracies and misrepresentations about Tim and Faith. We aren't going to comment on false statements that appear to have been sensationalized for the purpose of selling tabloid magazines."