Barack Obama hasn’t expressed his opinions about Donald Trump as publicly as others have, but even he has a breaking point.

Apparently, according to People magazine, after receiving a phone call from Trump last November, who suddenly professed his “respect” and “admiration” for him, Obama told a couple friends he’s nothing but a “bullsh*ter.”

One source said, “[Obama’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.”

Obama’s long-time friend and political strategist David Axelrod chimed in: “He’s very respectful of the appropriate role of a former president and that ex-presidents should not be looking over the shoulder of their successors and commenting on every decision. President Obama’s predecessor didn’t do that. Obviously, this now is a unique set of circumstances, but my sense is that he’s going to try and respect that tradition while reserving the right to speak out in given moments when things rise to that level.”