Barack Obama and Joe Biden’s ‘imperfect union’ revealed in new book

What bromance?

Former President Barack Obama once told an aide “Shoot. Me. Now” over Joe Biden’s constant rambling, a new book that sheds light on their allegedly fraught relationship claims.

The purported tension between the pair, which dates back to their time in the Senate, is laid bare in the upcoming book — “The Long Alliance: The Imperfect Union of Joe Biden and Barack Obama” — by New York Magazine national correspondent Gabriel Debenedetti.

Obama and Biden were repeatedly flanked by headlines of their so-called “bromance” during their eight years together in the White House.

But well before they took office, Obama’s first impression of Biden was “condescending” — and that he tended to “ramble, clearly loving every minute of it,” according to excerpts of the book obtained by the Daily Mail.

When Biden was giving a statement during George W. Bush’s confirmation hearings for his secretary of state nominee Condoleezza Rice in 2005, Obama passed a note to a staffer that read, “Shoot. Me. Now,” the book claims.

Obama also reportedly once told his close advisor David Axelrod that “Joe Biden is a decent guy but man, that guy can just talk and talk. It’s an incredible thing to see.”

Elsewhere, the book claims Biden “rolled his eyes behind Obama’s back at his aloofness and glad-handing with fellow pols” and was surprised by his so-called “humorlessness.”

Obama, however, thought that Biden’s repeated gaffes in public would give their rivals “ammunition.”

Their relationship improved when Biden became Obama’s right-hand man and they hosted weekly meetings together, the book claims.

But after the Democrats suffered heavy losses in the 2010 midterm elections, Obama considered asking Hillary Clinton to be his running mate in 2012, according to the book — even though Obama denied that rumor publicly at the time.

Biden was reportedly “distraught” over the prospect of being replaced, the book says.

Then, in 2012, Biden was accused of “betrayal” for publicly saying they both supported gay marriage — despite Obama planning to make the revelation in an upcoming TV interview.

Biden’s move left Obama “pissed,” according to the book.

The relationship between Biden and his former boss has been a point of intrigue in Washington — even after Biden became president.

Then-White House press secretary Jen Psaki was asked to address their friendship in April last year after being asked how involved Obama was in the current administration.

Paski said Obama and Biden “remain close friends and they talk regularly.”