Prince Harry and Meghan Markle hold hands in public. They also rub each other's backs and link arms as if it is a natural thing. They have been photographed kissing in public. However, that is quite different from what Prince William and his wife do in public.

There is a reason they don't hold hands or show affection, and this might shock some folks, but after Prince Harry and Meghan get married, they won't do it either if they follow the examples of other married royals. They have about six more months for their public displays of affection (PDA) to be seen.

After they say "I do" at Windsor Castle in May and give that first kiss as husband and wife, the public will rarely see that PDA again (if at all).

William and Kate have been married since 2011, and they have been seen kissing only three times. Two of those times were on the balcony after they first got married when fans asked for a do-over after the first kiss.

No more PDA

When Harry and Meghan made their first appearance together at the Invictus Games in Toronto last September, the affection was clearly on display, as it was when they announced their engagement on Monday, November 27. This happened again on Friday when they carried out their very first royal duties together in Nottingham.

You don't see Prince William and Kate showing affection, and you don't see Queen Elizabeth and Prince Philip showing affection either.

The same situation exists with Prince Charles and Carmilla Parker Bowles. Watch them the next time they are out and about, and you will observe that they rarely touch each other.

William and Kate prefer to keep their private feelings and professional duties separate when they are carrying out royal duties. They are working on behalf of Queen Elizabeth and representing her.

Therefore, they follow her example and do what she does.

Longtime royals writer Judy Wade explains that different occasions call for different behavior. For instance, we have seen William and Kate get excited and touch each other at sporting events.

Unity and celebration

Royal etiquette expert Myka Meier told People magazine that the young couple probably shows affection in public to demonstrate their unity and warmth for each other.

She says their gestures make them relatable to the public. While there is no written rule that couples can't show affection in public after marriage, it is rarely done.

It is obvious that Prince Harry and Meghan's marriage will bring a freshness to the royal family. The 33-year-old prince has been known to break rules in the past. So far, it appears that Queen Elizabeth and Kensington Palace are allowing him and his 36-year-old financée to deviate from more formal codes of conduct.