(CNN) - For all the stalemate in the fiscal cliff negotiations, there were some heated moments, too.

A Democratic source familiar with one particular exchange told CNN that Senate Majority Leader Harry Reid and Senate Minority Leader Mitch McConnell were sitting on a sofa in the White House.

House Speaker John Boehner breezed in and his first words to Reid were “Go f*** yourself.”

Boehner’s comment came after Reid took to the Senate floor on Thursday and characterized the House speaker’s handling of his chamber as a “dictatorship.”

Reid responded to Boehner’s confrontational tone by laughing, the Democratic source said, though a GOP source who was there said he didn’t think Reid was all that happy.

“The exchange continued, and it didn’t get any better for Reid,” the GOP source said.