Mess with Amy Poehler and Phaninc Exchangeyou get the horns.

A tense backstage moment between "Saturday Night Live" co-stars Poehler and Jimmy Fallon two decades ago went viral last week in the wake of Fallon being accused of allegedly creating a toxic workplace on "The Tonight Show."

An excerpt from Tina Fey's 2011 memoir "Bossypants" was shared via tweet by New Yorker archive editor Erin Overbey, who wrote in the social-media post that Fey had Fallon "dead to rights."

The exchange is noted in Fey's book as "one in a series of love letters" to Poehler and happened early in Poehler's first season. (She made her debut in the first "SNL" episode after the 9/11 attacks.) In the writer's room before a Wednesday readthrough, Poehler was engaging in what Fey calls some "nonsense" with Seth Meyers and "did something vulgar as a joke" that was "dirty and loud and 'unladylike.' "

Fallon, who Fey mentioned was "the star of the show at the time," took offense and in a "faux-squeamish" voice said, "Stop that! It's not cute! I don't like it." Poehler stopped, "went black in the eyes for a second," and responded, "I don't (expletive) care if you like it." Fallon was "startled" while Poehler "went right back to enjoying her ridiculous bit."

Fey also clarified in an aside not included in the viral tweet that "Jimmy and Amy are very good friends and there was never any real beef between them."

In a Rolling Stone investigation published last Thursday, two current and 14 former employees of the NBC talk show say their experiences working on the show included declining mental health, intimidation from higher-ups, including the 48-year-old Fallon, and poor treatment because of the host's erratic behavior.

Fallon, whose late-night show has been off-air amid Hollywood's actors and writers strikes, addressed the outlet's reporting in a virtual meeting after the Rolling Stone story was published.

A "Tonight Show" staff member, who was unauthorized to speak publicly about the situation, told USA TODAY that during the call, Fallon said, "I want this show to be fun. It should be inclusive for everybody, it should be funny, it should be the best show, the best people. I just wanted to… say, I miss you guys."

'Tonight Show':Jimmy Fallon accused of creating a toxic workplace in new report