The DIY SOS star and quiz show king, who has three older children, sons Charles, 20 and TJ, 18 and 19-year-old daughter, Tuesday, reveals in this week's HELLO! that he is expecting a baby boy this summer with his stunning 26-year-old wife Jessica, whom he wed in Rome in September 2012.
Reflecting on having a child later in life, the strapping game show host tells the magazine: "Earlier it did hit me, 'When he's 16, I'll be 67. Blimey!' But I'm a bit of a Peter Pan in spirit and physically I keep myself pretty fit.
"Jess has already been trying to extend my life by reducing the number of pork pies and bacon sandwiches I eat and although I still smoke, I've cut down a lot." But he reveals that he won't be in the delivery room when the baby is born – on the orders of his pretty young wife.
"Giving birth is a very physical process and I don't want him to see me in that vulnerable state. I prefer a little bit of smoke and mirrors. I don't think it would be beneficial to our relationship or to me to have him there and I have always taken that view," explains Jessica, who runs an antiques business and design consultancy.
"If Jess wanted me there, then of course I would be there, but I certainly don't feel offended that she doesn't. I'll be right outside, so I'll still be one of the first to hold our son," says Nick.
"Men will tell you that they want to be at the birth but it's because they think they ought to be.
"Admitting that you're not going to be there provokes the most extraordinary reaction, as if it's an abdication of responsibility, but the fact is, it was only in the Sixties and Seventies that men started to be there at births.
"There's a huge amount of guilt, fear and worry on a man's behalf when their partner gives birth, along with a feeling of complete uselessness, so I'm more than happy to take Jess's lead on this."
For the full interview, read this week's HELLO!. And for extra photos, video and enriched content, download our iPad app from Apple iTunes here.