'X Factor' Contestant -- My Long-Lost Son Knows I'm His Daddy!

"X Factor" contestant Chris Rene got two pieces of good news this week -- he made it to the next round of the show ... and his long-lost son learned Chris is his biological father.

Chris had a son six years ago named Elijah that he never knew about, who ended up in foster care. Chris and the boy were re-united four years ago, but the foster parents referred to Chris (who has another son who is 3) only as a close family friend.

But Chris -- who we're told has spent an enormous amount of time with Elijah -- posted on his Facebook page today that Elijah asked his foster parents who his real dad was. The foster parents asked the boy to guess ... and he guessed it was Chris.