Former President George W. Bush greeted his successor President Barack Obama at President Jimmy Carter’s funeral in a way which caught viewers’ attention Thursday.

The moment, caught on camera, showed the Republican tap the Democrat’s belly as he approached his seat at the Washington National Cathedral.

Interactions between former and current presidents are often watched closely at formal events such as Thursday’s funeral, particularly between those who have been vocal in their political differences over the years.

Obama was sitting next to President-elect Donald Trump, whom Bush appeared to ignore as he approached his seat, despite the pair both being Republicans.

The five living current and former presidents were in attendance at the state funeral in Washington, D.C., namely Joe Biden, Bill Clinton, Barack Obama, Donald Trump and George W. Bush, as well as vice presidents and first ladies.

Over the years, Obama and Bush have voiced their differences on policy, such as over the Iraq war, but have always maintained a professional and even friendly relationship. At times, the pair have worked together on initiatives such as disaster relief.

Thursday’s interaction, in which Bush tapped Obama on the stomach before taking his seat, appeared to continue that friendly relationship. The latter did then also speak with Trump throughout the ceremony, also appearing to joke together.

Other moments between the group also caught viewers’ attention, including Trump and his former Vice President Mike Pence shaking hands, and the apparent lack of conversation between Vice President Kamala Harris and First Lady Jill Biden, despite sitting next to one another.