John Stamos Is Joining 'American Idol' for a Special Reason!

John Stamos is joining American Idol! The 57-year-old star is set to join the current season as a guest mentor, ET reported Tuesday (April 27). PHOTOS: Check out the latest pics of John Stamos If you’ve been following along for the ride, you’ll already know that this season’s Top 9 will be taking a trip [...]