The Duke of Cambridge Prince William
Prince William, seen here with Kate Middleton, is called "One Pint Willy" by Mike Tindall. Photo: Getty Images/Gareth Fuller Getty Images/Gareth Fuller

Mike Tindall shares a close bond with his cousin-in-law Prince William, so much so that he is not afraid to call him with a rather cheeky nickname and reveal it to the public.

The former rugby star and his equestrian wife, Zara Tindall, were asked what monickers they call some royal family members during Wednesday's appearance on the "Seven: Rob Burrow" podcast on the BBC. He shared that he has a nickname for the Prince of Wales' inability to drink more than just one pint of beer.

Mike confessed: "The Prince of Wales is known to me as 'One Pint Willy' because he's not the best of drinkers, coming from a sport where it is built on the social aspect and a couple of beers being sunk quite often. That is one I will give away for the Prince of Wales."

Realising what he had revealed, he laughed and said: "Oh my God. It's out there now. Sorry sir," to which Zara jokingly taunted him: "You're in so much trouble!" She then added that "a lot of those nicknames kind of fly around".

The topic came up after Rob Burrow asked the couple if they have any pet names for each other. Mike shared that they "basically call each other 'munchkins' a lot" or "my love". He then quipped that he would leave it to his wife to disclose his contact name in her phone.

Zara agreed that "munchkin" is one of their most commonly used nicknames. But she said she also refers to her husband lovingly as "Mikey" or sternly as "Michael Tindall," especially when he is "not listening". The 42-year-old equestrian, who is the daughter of Captain Mark Phillips and Princess Anne, also teased that she has a NSFW contact name for her husband.

She shared: "He is in my phone as something else, and it ends with 'kitten,'" to which Mike interrupted with a laugh and said: "You can fill the first word in."

Mike and Zara have been married since 2011. They share three children: daughters Mia, nine, and Lena, five, and son Lucas, two.

Aside from "One Pint Willy" another nickname for Prince William is "Big Willy," which Kate Middleton reportedly used to call him during the early days of their relationship. But her nickname for the future king has since changed. The Princess of Wales allegedly refers to her husband as "Prince Baldy" because of his thinning crown. Meanwhile, Prince Harry, in his memoir "Spare", refers to his older brother as Willy.