Diana loved pranks and practical jokes, and one of the most uproarious involved an item purchased on a wild staff night out in Paris, during her official visit to France in November 1992.
We all referred to it as 'Le Gaget', or the gadget - in fact, it was a sex toy.
I had persuaded Lady Sarah McCorquodale, her sister and acting lady-in-waiting during the trip, to secrete it in Diana's handbag the next morning.
The Princess discovered it while going through her bag, between meetings with the French president Jacques Chirac and Paul McCartney.
Far from being offended, she thought it very funny, and from that moment Le Gaget became her secret mascot on all royal visits abroard.