Tina Fey Says She'll Only Join Social Media If She Can Show Her Nipples

The 'Sisters' star joined pal Amy Poehler at the junket for their upcoming film.

Tina Fey and Amy Poehler are teaming up again in Sisters, their upcoming comedy about two grown siblings who return to their childhood home and throw one last rager.

While the Saturday Night Live alum have shared hosting duties at the Golden Globes and made a cameo appearance as entertainment reporters in Anchorman 2, they haven’t really shared the big screen since 2008’s Baby Mama.

“I think people think we work together a little bit more than we actually have,” Poehler told ET at the Sisters junket on Thursday. “We don’t really act together as much as we’d like, and maybe America wants.”

They’re funny ladies, but the demand for more “TinAmy” is no joke, according to the Internet. A fan-run Instagram account dedicated to “the married couple Tina Fey and Amy Poehler” has nearly 19,000 followers, even though the comedians themselves shy away from social media.

“There’s just not enough hours in the day for it really,” said Fey, who is also currently in production on the second season of her Netflix series The Unbreakable Kimmy Schmidt. “We both work a lot. And if we have time that we’re not working, we want to be with our kids. I’m not going to be curating what my meal looked like for Instagram or something.”

WATCH: Amy Poehler and Tina Fey Reunite in Hilarious 'Sisters' Trailer

“I’m just waiting for it to catch on,” jokes Poehler, who only participates in social media via her Smart Girls organization. “We’ll see.”

“I’m just waiting to be able to show my nipples,” Fey added. “If I can't show my nipples, I don’t want any part of it.”

WATCH: Tina Fey and Amy Poehler's Best Golden Globes Jokes

Poehler and Fey have been friends for more than 20 years now, getting their start on the same improv team at Chicago’s Second City.

“We were both told separately, like, ‘This girl, you're gonna like her. You guys are gonna get along,’ and I think the fact that we were put together as teammates has really shaped us,” Fey said. “I think we really think of ourselves as teammates in every context.”

WATCH: 'Sisters' Star Tina Fey Jokes 40-Year-Olds Need to Party More Than Teenagers

“Yeah, it was kind of like an arranged marriage that worked,” Poehler agreed.

The ladies brought that chemistry to the small screen, working on SNL together for many years before making the leap to film in 2004’s Mean Girls. While their latest raunchy comedy shows the pair taking on slightly different roles -- Poehler as the buttoned-down good girl and Fey as the wild child -- the ladies describe the film as “a very sweet story about sisters.”

WATCH: Julia Louis-Dreyfus Celebrates Her 'Last F**kable Day' with Tina Fey, Patricia Arquette and Amy Schumer

They’ll be up against some tough competition at the box office, however. Sisters is set to debut opposite a little film called Star Wars: The Force Awakens.

“I think it’s going to be a very good weekend for movies,” Poehler told ET diplomatically at her Hollywood Walk of Fame ceremony on Thursday when asked which was stronger: The Force, or the bonds of sisterhood. Her 5-year-old son Abel, however, was less supportive.

“Star Wars!” he exclaimed.

hits theaters Dec. 18.

WATCH: Amy Poehler and Tina Fey On How Their Kids Would Describe Them