It was only a matter of time before comity spread throughout the family.

George H.W. Bush was in his mid-eighties by 2010, when an earthquake devastated Haiti. He was too old to brave another road trip, according to “The Presidents Club,” so suggested his son as Clinton’s traveling buddy.

The two men were slightly shy about partnering at first, the authors write; the elder Bush had to ask President Barack Obama to formally invite them to make the trip together.

But they went to Haiti, and helped raise tens of millions of dollars for relief, and inevitably began exchanging gifts. “Bush sent Clinton foodstuffs from Texas; Clinton liked to send books and music,” according to the authors.

Family matriarch Barbara Bush, whom a younger Clinton had liked no more than he liked her son, according to the book, now calls Clinton her son’s “fourth brother,” Bush told an interviewer in 2010.