Prince Louis’s christening took place in the Chapel Royal, St James’s Palace on July 9, 2018.
All his immediate family were in attendance, including the recently married Meghan Markle and Prince Harry.
When the Royal Family entered the chapel they were greeted by the Archbishop of Canterbury Justin Welby.
Kate, Princess of Wales chatted to the Archbishop for some time as she was holding her then three-month-old son.
Behind her stood the Duke and Duchess of Sussex as they patiently waited to greet Archbishop Welby.
Judi James, a body language expert spoke exclusively to Express.co.uk to explain why Kate took a while when speaking to the Archbishop, and how this might have made the Sussexes feel.
She claimed: “Royal bottlenecks are common at events like this, where a reception line will often lead to some of the speedier royals queuing behind the ones at the front.
“Many events have someone on usher control to gently steer the ones at the front through so the ones waiting don’t have to stand looking awkward, but Harry is left looking exceptionally awkward here as he and Meghan stand waiting behind a rather chatty-looking Kate.
“Harry arrives performing several gestures of discomfort, fiddling non-stop with his jacket and tie; rolling his shoulders as though bracing himself; kicking his feet out impatiently, fiddling with his ring and then wiping his mouth with one hand.
“Meghan adopts a polite smile but grinding to a halt to wait behind Kate as she chats to the Archbishop does seem to raise Harry’s anxiety levels.”
The body language expert explained the most likely reason why Kate did not move on quickly from the Archbishop.
Judi claimed: “Kate could of course have moved on more quickly to let Harry and Meghan snap into action but, unlike most other royal events, this christening was her day and her baby son’s day, so a few extra words in front of the cameras would easily be more appropriate than rushing.
“Everyone is expected to coo over a new baby and Kate looks delighted at the chat here.
“Rather than lingering deliberately, she does use an eyebrow flash at one point to announce the chat is ended.
“This would show her having a level of skill similar to the late Queen when it comes to gently and silently using announcement gestures to steer a conversation.
“But it’s the Archbishop who seems to add to the conversation when Kate is partly walking away.
“Kate is polite but she again ends the conversation non-verbally so if anyone is to blame for the Sussexes plight here it’s more the friendly Archbishop than Kate.”