Given how obviously besotted the Duke and Duchess of Cambridge are with one another, it has been noted that they rarely hold hands in public - but why?
It turns out the reason is surprisingly simple.
According to Robin Kermode, a body language expert and founder of communications coaching company Zone2.co.uk, it’s all because of the Queen, he told the Mail.
Her Majesty rarely holds hands with husband Prince Philip in public and, while Robin explains that there’s no official rule in place against PDA’s, the Queen has set a precedent for other royals.
The monarchy is allowed to be physically affectionate but they choose not to as a matter of decorum.
Prince William and Kate Middleton’s visit to India
Prince William and Kate Middleton’s visit to India
Prince William and Duchess of Cambridge pose next to a prayer wheel on the trek up to Tiger's Nest during a visit to Bhutan
Duke and Duchess of Cambridge, turn prayer wheels halfway up the trail leading to a Buddhist monastery referred to as the "Tiger's Nest" (top L) on their two-day visit to Bhutan
The Duchess of Cambridge reacts after firing an arrow at an archery event in Thimphu
Britain's Catherine, Duchess of Cambridge looks on as she watches Prince William prepare to fire an arrow at The Changlingmethang National Archery ground in Thimphu
The Duke and Duchess of Cambridge arrive into Paro International Airport for the first day of a two day visit to Bhutan
Prince William and Catherine, Duchess of Cambridge, paint an elephant statue at Kaziranga Discovery Park in Panbari village, in Kaziranga, some 250 km from Guwahati, the capital of the north-eastern state of Assam
Britain's Catherine, Duchess of Cambridge, feeds a baby elephant at the Centre for Wildlife Rehabilitation and Conservation (CWRC) at Panbari reserve forest in Kaziranga in the northeastern state of Assam, during the royal visit in India
Prince William and Duchess of Cambridge, meet a rhino calf at the Centre for Wildlife Rehabilitation and Conservation (CWRC) at Panbari reserve forest in Kaziranga in the northeastern state of Assam
Catherine and Prince William take a Game drive at Kaziranga National Park at Kaziranga National Park in Guwahati
Catherine, Duchess of Cambridge and Prince William visit a contact centre run by the charity Salaam Baalak, which provides emergency help and long term support to homeless children at New Delhi railway station
Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge meet a young dancer as they watch dancing by the fireside during a Bihu Festival Celebration at Diphlu River Lodge
The Duke and Duchess of Cambridge meet Prime Minister of India Narenda Mod in New Delhi's Hyderabad House during day three of the royal tour to India and Bhutan
Catherine and William visited the Banganga Water Tank. They were given a traditional welcome at Bangana Water Tank and met representatives from SMILE, an organisation working in an economically deprived urban area to support local enterprise
Duchess Of Cambridge enjoys a game of cricket during a visit to meet children from Magic Bus, Childline and Doorstep, at Mumbai's iconic recreation ground, the Oval Maidan
Prince William and Catherine Duchess of Cambridge at India Gate in New Delhi
Prince William and his wife Catherine take part in an event at the Gandhi Smriti, a museum dedicated to Mahatma Gandhi, in New Delhi
Prince William and Duchess of Cambridge meet young entrepreneurs during a visit to Mumbai
The Duke and Duchess of Cambridge prepare to lay a wreath at the Inida Gate in New Delhi
The Duke and Duchess of Cambridge remove their shoes at Gandhi Smriti in New Dehli, India before paying their respects at the Mahatma Gandhi memorial
The Duke and Duchess toured the museum housed in the Old Birla House and paid their respects at the place where Mahatma Gandhi's life ended on 30 January 1948
Duchess of Cambridge and Prince William pose for a picture at India Gate Memorial
Prince William and Catherine pay their respects at the place where Mahatma Gandhi's life ended on 30 January 1948, at Gandhi Smriti, the Old Birla House museum
The Duke and Duchess of Cambridge poses with local school children as they tour Old Birla Hous in Gandhi Smriti in New Dehli
The Duke Duchess of Cambridge meet children from local charities Magic Bus, Childline and Doorstep, and join game of cricketwith boys from the Dilip Vengsarkar Academyat the Oval Maidan recreation ground
The Duke and Duchess of Cambridge are garlanded as they arrive at the Banganga Water Tank in Mumbai
Catherine, Duchess Of Cambridge plays football during a visit to meet children from Magic Bus, Childline and Doorstep
The Duke and Duchess of Cambridge react after playing football during a visit to the Banganga Water Tank in Mumbai
Duchess of Cambridge and Prince William play football games during a visit to the Banganga Water tank, where they met representatives of SMILE
The Duke and Duchess of Cambridge arrive at a Bollywood Charity Gala hosted by the British High Commission and the British Asian Trust at the Taj Mahal Palace hotel in Mumbai
Catherine, Duchess of Cambridge arrives for a Bollywood Inspired Charity Gala at the Taj Mahal Palace Hotel
Prince William and Duchess of Cambridge speak with Boman Kohinoor during a meeting in Mumbai
The Duke and Duchess of Cambridge stand after laying a wreath on the martyrs memorial at the Taj Mahal Palace Hotel in Mumbai
Robin also explains that the couple, which have been married since 2011, do not feel the need to prove their love, especially when on official state business.
He notes that some public figures use hand holding as a deliberate act to prove that their relationship is solid, but this isn’t something Prince William and Kate struggle with.
It’s a tactic Robin says can most recently be seen with President Donald Trump, who by holding on to the hands of leaders for too long, Robin believes he is trying to maximise photo opportunities.
After nearly six years of marriage and two children, there’s no doubt that the couple are very much in love. They simply choose to remain professional when they are out and about as representatives of the British monarchy.