No one ever said Barack Obama was going to keep it classy.

The 44th president went away for a while, kite boarding in the Caribbean at a billionaire's private island, hobnobbing with Hollywood celebrities on a super-yacht in Tahiti. But then he came back, mostly to deliver a $400,000 speech to a big financial institute (wasn't he against those as president? Oh, never mind.)

Sadly, unlike his predecessor, George W. Bush -- who famously left the limelight, saying the job of president is hard enough without a former president running his mouth nonstop -- Obama longs to still be part of the daily conversation.

And so do his former aides and friends. Obama's National Security Adviser, Susan Rice, this week delivered a scathing speech targeting President Trump. Now, two friends of Obama's have told People magazine exactly what the former president says in private about his successor.

“He’s nothing but a bullsh–ter,” Obama told two friends early last November, describing an election night phone call with Trump, in which the businessman suddenly professed his “respect” and “admiration” for Obama—after years of hectoring.

Speaking to PEOPLE for its new cover story on Obama and his wife Michelle adjusting to life outside the White House, the two friends quoted Obama’s blunt assessment of President-elect Trump. And how has Obama’s opinion changed since Trump been in office? “Well,” said one of the sources, “it hasn’t gotten any better.”

A third source close to Obama tells PEOPLE: “He’s deeply concerned with what he’s seen. But he’s also optimistic and heartened that citizens aren’t just watching it happen but engaging with neighbors and elected representatives at town halls.”

“Bulls—ter,” while head-turning, shouldn’t come as a huge surprise to anyone paying attention to Obama’s 2016 campaign rhetoric on Trump (“unfit,” “woefully unprepared” and “unacceptable”). But the former president has been meticulous since the election about not publicly violating that unwritten code of conduct among ex-presidents that bars criticizing whoever’s currently in the Oval Office.

Now isn't that special?