During a holiday to Ibiza, five years before getting married, Kate Middleton allegedly had to warn Prince William to behave himself and not create a "bad impression" as future King.

In a Vanity Fair report, royal expert Vicky Ward claims that the Duchess of Cambridge was on hand to remind her then-boyfriend how he should be conducting himself when he was riding around on a moped in plain sight.

According to a report in Woman&Home on holiday in 2006, Prince William and Guy Pelly, an old friend in the group, often referred to as the 'court jester', were careening around on mopeds in front of a rented house in Ibiza.

Recounting Kate's strict moment of reining William in, Vicky added, "According to a source, Middleton came out of the house and, matron-like, told them to stop. She said, ‘Anyone could be watching! Go out the back and stop behaving like this,’ according to Woman&Home.