Former President George W. Bush made his successor, Barack Obama, noticeably snicker at a joke delivered during Bill Clinton’s speech at a hurricane relief benefit concert in Texas.

As Clinton discussed the importance of offering ongoing support to the communities affected by hurricanes Harvey and Maria, Bush leaned over and quipped something to his successor, immediately eliciting a laugh from a Obama, whose reaction garnered much positive attention on social media.

All five former living US Presidents attended “Deep from the Heart: The One America Appeal” at Reed Arena at Texas A&M University in College Station.

Musician Lady Gaga made an unbilled appearance and tweeted, “Nothing more beautiful than everyone putting their differences aside to help humanity in the face of catastrophe. #OneAmericaAppeal.”

The singer made a “generous” donation, said Jim McGrath, a spokesman for George H.W. Bush.

The elder Bush followed up the concert Monday morning with a joke of his own, saying he would have sung a duet with the pop star — “if asked.”