WATCH: MSNBC’s Joe Scarborough flares with anger when guest asks him to stop interrupting Mika Brzezinski

MSNBC's Joe Scarborough bristled when a guest stopped him from talking over his co-host and fiancée, Mika Brzezinski.

"Morning Joe" hosted historian and author Rick Perlstein to talk about his recent New York Times op-ed, "Our Hackable Political Future."

Perlstein tried to put disinformation campaigns spread by Facebook and Twitter into historical context, and Scarborough said lawmakers such as Sen. Kamala Harris -- who appeared on the show the previous day -- were reluctant to punish social media giants for their roles in election hacking.

"It goes back to money," he said. "Why doesn't Kamala Harris want to come on our show -- and we're so glad she did -- but why wasn't she aggressively going after Facebook and Twitter?"

Brzezinski suggested playing back Harris' comments, but Scarborough continued with his point.

"She represents them," he said. "She's in California, she represents them and if she's going to run for president -- this, by the way, applies to everybody running for president, not just her -- you don't want to cross Facebook."

Brzezinski disagreed, but Scarborough was unconvinced.

"Don't kid yourself, they all will -- they all will have trouble and that is where we stand," Scarborough said, and then started to pose a question to Perlstein. "I want to ask you before we go."

Perlstein, however, stopped Scarborough.

"Joe, I think Mika was trying to say something there," Perlstein said, and Brzezinski giggled. "What were you saying, Mika?"

"I just don't think Kamala Harris will have a hard time crossing Facebook and these companies when she is across the table from them," Brzezinski said. "I think she's trying to work with them which is why she wasn't strong on the show yesterday."

Scarborough seemed annoyed by the interruption, and asked Perlstein if he had experienced a technical difficulty.

"I'm curious, did your earpiece go out -- did you not here that before?" Scarborough said, and then asked the show's director if there had been a problem. "I knew she was trying to say something. Alex? Alex? Is Rick's ear piece working?"

Perlstein assured the host his earpiece was fine, and Scarborough later tried to joke off the incident.

"Am I interrupting you again?" Scarborough asked, as Brzezinski tried to take them to a commercial break. "Is there anything else you wanted to say? You said Kamala Harris could stand up -- I heard that. I would feel horrible if Rick thought that I interrupted you."

Brzezinski repeated her assertion that Harris could be a "force to be reckoned with," and Scarborough flirted with his wife-to-be.

"You know, I think you're right," he said. "You're always right."

WATCH: Morning Joe bristles when guest Rick Perlstein asks him to stop interrupting Mika from Travis Gettys on Vimeo.