AT HOME IN THEIR PALATIAL MAYFAIR MANSION JOHN CAUDWELL AND HIS PARTNER MODESTA INTRODUCE BABY ISABELLA - A LITTLE SISTER FOR SON WILLIAM

When HELLO! arrives at the  magnificent Mayfair mansion of John Caudwell and his partner Modesta Vzesniauskaite, it is a hive of activity

- EMILY HORAN

Amid the opulence of a sweeping white marble staircase lit by five dazzling crystal chandeliers, squeals of delight emanate from the couple's two-year-old son William, who is excitedly putting on his "party clothes" for HELLO!'s exclusive photoshoot, which captures the first family photos since the arrival of his baby sister, Isabella Sky, three months ago.

The angelic newborn daughter of entrepreneur and philanthropist John, 70, and former Olympic cyclist Modesta, 39, snoozes serenely in her mother's arms despite the hubbub - much to her parents' delight.

"Isabella is unbelievably easy, which is exactly what we needed, because William is the opposite," Phones4U founder John tells us with amusement as he and Modesta open the doors to their jawdropping London home.

“I always dreamt of having a son like John and a daughter like me,” says Lithuanian-born Modesta, adding: “I think Bella will be just like me. It’s a nice balance and much appreciated, given that William John is such a live wire.”

FAMILY JOY 

Isabella, who was born at 10.40pm on 27 March at Princess Grace Hospital in Monaco, where the family also have a home, has proved a perfect playmate for little William.

“It’s special to watch him bond with her,” their proud father says. “He absolutely adores her: he kisses her feet, hands, head, face. We’ve always called Isabella ‘William’s sister’ rather than ‘our daughter’.”

Indeed, William is on top form during today’s shoot, chatting away as he leads us from room to room.

The toddler certainly knows his way around – but this is no ordinary family home.