Kate and William have been spotted in their own form of public displays of affection in recent months.
The couple, who welcomed their third child Prince Louis in April, have been pictured holding hands and whispering at several events.
The Cambridges normally reserve such intimate gestures for major family photo calls, such as their engagement or welcoming to their children to the world on the steps of the Lindo Wing.
Royal fans have also noticed that William has been placing a protective and on the small of Kate's back at several events.
Speaking to FEMAIL, body language expert Judi James said: "Now that Meghan has joined The Firm, her own determinedly tactile behaviour with Harry does seem to have had a profound 'echo' effect on William and Kate's rituals.
"Normally its a younger sibling that will mimic or mirror the older, but in Harry and William's case it seems to be William taking his lead from his younger brother and his wife."