Beckham believes the former Spice Girl-turned-fashion designer will always be one step ahead of him in the industry and is extremely proud of her success, reported Contactmusic.
When asked about competition between the couple, he said, "She would definitely win. (What she's) created and achieved in a few short years, going from a Spice Girl to a respected fashion designer. It's really inspiring to see."
The 39-year-old star, who is also the face of British brand's 2014 global ad campaign, said he jumped at the chance to design for Belstaff.