It's a small club, the people who have been U.S. president - there are only 5 of them alive now, including President Barack Obama. It's good to find out that they get along, too, in a friendly fashion.
Ex-presidents Bill Clinton and George W. Bush took fun swipes at each other on social media, all over Bush's loving biography of his father, another ex-president, George H.W. Bush.
Clinton, who is friendly with the Bush family, was sent a copy of the book "41: A Portrait of My Father." He wanted to respond to Bush directly, but discovered that Bush 43 isn't on Twitter.
So, he tweeted at him to shame him a bit.
— Bill Clinton (@billclinton) November 12, 2014
@billclinton tweeted: Received my copy of #41 by #43, George W. Bush. Touching tribute! #HowAreYouSTILLNotOnTwitter #PresidentialTweeters
Bush did answer, but not on Twitter. He took to his own favorite social media, Instagram, to take a playful swipe back at his predecessor.
@georgewbush: Thanks, 42. Hope you like the book about your pal, #41. #HowAreYouSTILLNotOnInstagram #PresidentialGrammers #BrotherFromAnotherMother