Already prepping for a royal heir?

Prince William and Kate could have ordered anything and everything (courtesy of a private butler) to eat and drink during their super-luxe honeymoon in the Seychelles -- so why in the world did they order cream cheese and Brussels sprouts in advance of their arrival?!

Royal watcher Katie Nicholl reports in the new Vanity Fair that William, 28, requested that their private villa be stocked with the funny combo; interestingly, brussels sprouts, high in folic acid, are said to aid in fertility.

And Prince William and Princess Catherine (their reported preferred titles, Nicholl writes) watched their wedding after the fact (wearing terrycloth robes!) in between receptions on April 29.

"It was just the two of them, and they were so excited to actually see it on the television," a Palace aide told Nicholl. "Harry joined them afterwards, and they were all in high spirits."

A highlight? When little bridesmaid Grace van Cutsem famously scowled on the palace balcony! "They were laughing when the cameras panned onto little Grace on the balcony, and William was saying, 'Poor Grace, she looks terrified!'"

Nicholl also reveals a touching wedding reception toast from the Princess' dad Michael Middleton. "I knew things were getting serious when I found a helicopter in my garden," he told the revelers. "I thought, Gosh, he must like my daughter. I did wonder then how William was going to top this if they ever got engaged."

Back home in Anglesy, the royal couple are keeping it simple for now. They have turned down Prince Charles' offer of a larger staff, and Kate has delayed appointing her ladies-in-waiting -- but has been invited to join the R.A.F. Wives Club.

And when they travel to Canada and the U.S. in June and July, their entourage will be limited to just 6 to 10 people -- and no valets, despite Kate's numerous daily wardrobe changes.