Simon Cowell had a ''really protective'' instinct when his son was born.

The music mogul recently became a father for the first time and after meeting two-month-old Eric - who he has with girlfriend Lauren Silverman - he had an urge to make sure he was ''safe and looked after''.

The doting dad said: ''The second he was born I felt this really protective instinct towards him to make sure he was safe and looked after. I've always had that nature though. With friends and family and with animals. It's something I have.''

Simon - who has a brother, Nicholas and three half-brothers, John, Tony, and Michael - claims his mother Julie Brett still couldn't believe he'd become a father until she met the tiny tot for herself as it was such a shock to her that her son was having a child of his own.

The 54-year-old star told HELLO! magazine: ''It was fantastic. I was really looking forward to that moment, because of all her sons I was the one who she was convinced would never have kids.

''I'm not sure she even believed it until I actually said, 'This is your grandson'. But it was a great moment. She's hilarious, my mum - a real character. It was a big day for her.''