The friendship between former first lady Michelle Obama and former President George W. Bush was on display again Thursday at the Obama Presidential Center's opening ceremony in Chicago. 

Ahead of the ceremony, Bush gifted Obama a tin of Altoids in a callback to one of their viral moments at the funeral for Sen. John McCain in 2018. The former president was caught sneaking Obama what was later said to be a cough drop during the funeral. 

"President Bush and I, we are forever seatmates because of protocol, that's how we sit at all the official functions, so he is my partner in crime at every major thing where all the 'formers' gather," Obama said on "Today" after the moment caught the public's attention. "It was a simple gesture. He was getting a cough drop from Laura, and I looked over and I said, 'Hand me a cough drop.'"

Obama called Bush "a wonderful man" and "a funny man." 

"I love him to death," she said.

Months later, Bush recreated the moment at the funeral for his father, appearing to slip Obama a piece of candy or a mint when they shook hands.

In a recent interview with his daughter, Jenna Bush Hager, Bush referred to what he handed Obama at McCain's funeral as an Altoid. 

But whether it was a cough drop or a mint, the sentiment remains. 

"It turns out the country is starved to see a White center-right Republican and an African American center-left Democrat having fun and being able to converse, not as political figures, but as citizens," Bush said. 

And the gift on Thursday appeared to be well received, with Obama smiling and holding up the tin in a photo with Bush. 

Bush and his wife, former first lady Laura Bush, along with the other "formers" — Bill and Hillary Clinton and Joe and Jill Biden — sat with the Obamas on the stage at the presidential center ceremony Thursday.