"M'am, not Mum!" said the retired rugby star, who is married to the Princess Royal's daughter, Zara Mike Tindall knows just what to call his royal mother-in-law, Princess Anne. On Nov. 4, the retired rugby star made the revelation while appearing on Good Morning Britain to discuss his new book,

Mike Tindall has given a unique insight into his close bond with Princess Anne - including what he calls his mother-in-law behind closed doors. The former rugby professional married Zara Tindall - who is Princess Anne 's only daughter - back in 2011. The pair, who met in 2003, now share three children - Mia, 10, Lena, six, and three-year-old Lucas.

Former rugby player Mike Tindall appeared on Good Morning Britain with James Haskell to chat about their new book The Good, the Bad and the Rugby - Unleashed

Mike Tindall has been part of the Royal Family for over a decade after marrying Zara Tindall in 2011 and he has now revealed how he addresses his mother-in-law Princess Anne in private

Mike Tindall has been part of the Royal Family for over a decade after he married the daughter of Princess Anne, Zara Tindall, in 2011, and he has finally revealed how he addresses his mother-in-law in private.

Mike Tindall has highlighted the special roles that Princess Kate, Prince William and Princess Anne hold in the world of rugby. The former England international rugby player who is married to Princess Anne's daughter Zara Tindall has a strong bond with the senior members of the Royal Family.