Nigel Lythgoe has confessed his surprise at the news Simon Cowell is to become a father.
Simon, 53, has confirmed reports that he is fathering his first child with New York socialite Lauren Silverman.
Nigel admitted: "Yes, I seriously was. I thought he was a confirmed bachelor.
"I don't think he thought this relationship would go anywhere. It was his best friend's wife. So, I think it came as a surprise to everyone really."
Asked what sort of father he thinks The X Factor boss will make, Nigel joked: "He'll probably tell the kid off, every day. 'You're leaving the house!'."
And he teased the baby would wear: "Nappies just a little too high, little black t-shirts."