Prince William, Kate Middleton, Meghan Markle and Prince Harry
Prince William, Kate Middleton, Meghan Markle and Prince Harry leave after attending Christmas Day Church service at Church of St Mary Magdalene on the Sandringham estate on Dec. 25, 2018 in King's Lynn, England. Getty Images/Stephen Pond

Kate Middleton and Prince William are not backing off from their rivalry with Meghan Markle and Prince Harry.

The Duke an Duchess of Sussex are very popular, but the Duke and Duchess of Cambridge refuse to be overshadowed. Due to this, royal correspondent Camilla Tominey warned the fab four of potential trouble ahead due to their social media clashes.

“What you have is a couple not wanting to be overshadowed, and a couple not wanting to be sidelined,” Tominey said on “This Morning.”

On Sunday, both the Cambridges and Sussexes shared series of family photos. Prince William and Middleton shared snaps of their family outing at the garden that the duchess designed for Chelsea Flower Show.

Prince William and Middleton took their three kids Prince George, Princess Charlotte and Prince Louis with them and the three children were obviously having a great time. It was the first time the public saw Prince Louis walking.

Earlier that day, Prince Harry and Markle shared never-before-seen behind-the-scenes pictures during their royal wedding. The couple shared them to celebrate their first wedding anniversary.

The Sussex Royal account posted the pictures 5 a.m. on Sunday. Kensington Palace shared the Cambridges’ photos around 10 p.m.

Due to Kensington Palace’s move, the Duke and Duchess of Cambridge were accused of stealing Prince Harry and Markle’s thunder. According to E! News’ Natalie Finn, at present, “it’s taboo to release photos on the same day that someone else releases photos – when that someone else is a very close relative.”

Royal aides told royal correspondent Richard Palmer that the publicity clashes between Middleton and Prince William and Markle and Prince Harry have already upset the palace. However, there was little they could do about Prince Harry and Markle’s wedding anniversary clashing with Middleton’s flower show.

Courtiers revealed that aside from this, there had been times when the couples overshadowed the other’s work. Among the royals, Prince Charles and Camilla Parker Bowles are at the hardest position.

“We've already had a situation with fears of overshadowing Prince Charles. Charles and Camilla have felt like sandwich generation - overshadowed by Queen, and overshadowed by younger royals beneath them,” Tominey explained.