GIRLS, IT TAKES IRON WILL TO BE A REAL PRINCESS…and PRINCE WILLIAM just discovered what a royal pain that can be when beautiful princess-bride-to- be KATE MIDDLETON – shedding her meek “Waity Katie” persona – gently but firmly informed her boyfriend-turned-betrothed that henceforth “there will be NO hanky-panky” until the April “I do’s” at Westminster Abbey… and their magical first night in wedding chambers.

Said a royal insider: “Will was stunned when Kate explained that there’s absolutely no way she’ll run the risk of ruining her big day with the embarrassment of an unplanned pregnancy. She told him, ‘Darling, I want our wedding night to be really special.’ Kate said Wills just kept saying, ‘You’ve got to be kidding…You are kidding, right?’ But Kate assured Prince Charming that it was no joke. She’s determined to do everything by the book to ensure that theirs will be the wedding of the new century.”

Conceding that a hands-off decree seems extreme after seven years as a cuddly couple, Kate told my source: “There is only one form of contraception that is absolutely, 100 percent foolproof – and that is abstinence.” So it’s bye-bye, Waity Katie…and hello, Chilly Willy.

(Just close your eyes and think of England, old chap!)