Prince William On The Fence To Join Kate Middleton's Parents Carole And Michael’s Vacation? Royal Family Celebrated Carole’s Birthday In Posh Mustique, Phones Banned

Rumors from the mill: was Prince William on the fence to be with Kate Middleton's parents, on Carole and Michael Middleton's vacation?

Prince William initially planned not to join the in-laws for Carole Middleton's 60th birthday in Mustique. Kate's hubby apparently decided to come along, though not as willingly as expected. Kate Middleton's parents, Carole and Michael's vacation in Mustique over the weekend was a very exclusive affair.

An E! News source said the royal couple was particular with the guest list for the party last Jan. 31. They even banned phones during the celebrations to ensure nothing leaks out.

"William and Kate have edited their friends so much that it's really a closed family affair, with just those who are very trusted and wealthy Mustique residents invited, and only the closest of friends from back home who have proven over the years their trustworthiness," the source said.

Photographers still managed to take a photo of Kate's parents before they jetted off to the exclusive island of Mustique and the party's posh venue, Villa Rocina.

Did tension with the in-laws brew in paradise? The Celebrity Laundry report said it's to be expected. "Feting" the in-laws could've been a chore for William, and the families' contrasting backgrounds might also be part of the reason why he hesitated to come along.

The event was indeed a hush-hush affair, but it was confirmed a cocktail party. It didn't leave pregnant Kate out of the fun, though. The select group of guests toasted with a signature cocktail, while Kate sampled a non-alcoholic, "mocktail" substitute.

"Brian [Kinsella of Goring Hotel] is being charged with making a special cocktail-a non-alcoholic cocktail-for Kate who is clearly pregnant and can't drink. He's naming it Mother's Mocktail," the E! News source confirmed.

Basil Charles from the local bar in Mustique concocted the signature champagne cocktail for everyone else. Kate Middleton's parents Carole and Michael Middleton's vacation peaked at the posh party, for Carole's 60th birthday.