This unseen photo of Kate and William has gone viral

Prince William and Kate Middleton aren't often affectionate in public. The Duke and Duchess of Cambridge are generally quite private when it comes to their relationship, rarely guilty of PDAs.

However, an unearthed and previously unseen photo of the pair has gone viral with many royal fans commenting on their 'chemistry' and noticing the loving and affectionate look that they're giving each other.

An Instagram fan account shared the picture on the social media platform, writing: 'Good night #dukeofcambridge #duchessofcambridge #duchesscatherine #princewilliam.'

Followers of the account were quick to comment, with one writing: 'Gorgeous couple.'

Another added: 'Those eyes tell all. They don't even have to say a word to each other as their eyes, communicate the intense love, adoration, affection, friendship, trust, respect, and loyalty they both share with each other. I wish that all could find such chemistry with their chosen partners. It is an amazing gift and a priceless Blessing.'

The snap was reportedly taken before they married in 2011, and there's no denying that they look very much in love. The couple celebrated their eight wedding anniversary earlier this year, and now share three children together - Prince George, Princess Charlotte and Prince Louis.

William and Kate choose not to hold hands in public, and according to body language expert, Robert Kermode, it’s all because of the Queen.

He previously told the Daily Mail that they are following in the footsteps of the Queen and Prince Philip, who are rarely affectionate in public.