United Kingdom, June 1 -- Mike Tindall has revealed the surprising nicknames he and wife Zara Tindall have for one another.

The former rugby star and his wife - who is the daughter of Princess Anne and her ex-husband Captain Mark Phillips - believe humour is the key to their successful relationship and as well as using terms of endearment for one another, they also have a comical couple's moniker.

Mike told the new issue of woman+home magazine: "We both refer to each other as 'munchkin' but if it's nicknames, it's Z and Mikey-T.

"You've always got to see the funny side!"

Mike and Zara are parents to Mia, 12, Lena, seven, and five-year-old Lucas, and while juggling the needs of their brood can be "stressful", the couple try to stay goo...