David and Victoria Beckham have shown their 20 year marriage is stronger than ever as their son Brooklyn shared a rare video of them looking loved up as they danced together at Harper and Cruz’s christening.The former professional footballer, 44, and the fashion designer, 45, who celebrated their 20 year wedding anniversary earlier this year, sing and dance during the intimate clip which was posted on 20 year old Brooklyn’s Instagram story.The footage shows Victoria and David dancing to a live