Billie Lourd and Leslie Grossman may be two decades apart in age, but they are BFFs.

The two actresses, who met while starring on the “American Horror Story” franchise, spoke about their powerful bond while chatting to Page Six at the Season 13 premiere at the iconic Chelsea Hotel on Wednesday night.

“We are the best of friends,” Lourd, 34, gushed. “This is the realest situation of all situations. This is literally top tier.”

Grossman, 54, concurred.

“This is my work wife, my life wife, my sister from another mister,” she enthused. “I love Billie Lourd with all my heart and soul.”

The “Scream Queens” alum explained that the duo speak nearly every day and joked that when “I’m rolling calls on the way back from pre-school, this (pointing to Grossman) is my first call that I roll.”

Lourd shares two children, son Kingston, 5, and daughter, Jackson, 3, with husband Austen Rydell.

She added that she and Grossman often have no news to report.

“She’s one of those people I’ll call and I’ll just be like, ‘Hey, what are you doing man? I’m driving,’ and that is a real friendship.”

The “Popular” alum remembered when she first met Lourd.

“When I met Billie, Billie wasn’t married; Billie didn’t have kids. [Now] Billie is married; she has two kids. She’s the most fantastic mom in the world, so this is really one of the greatest things this show has brought: the most amazing friendship. So this is my wife for life,” she raved.

Both of them agreed they never thought there would be 13 seasons of the spooky franchise.

“My first year, I thought it’d be one and done,” Grossman explained. “And, what a great experience and thank you and let’s move on, so every year [they ask me back], I’m like, ‘Ok, you want me back?’”

Lourd added that she will always be available for the “AHS” franchise.

“I’m not even tech avail, I’m full avail,” she joked.

Lourd and Grossman were joined by a slew of other stars for the splashy premiere, including Angela Bassett, Jessica Lange, Sarah Paulson, Paul Anthony Kelly, Mena Suvari and Gabourey Sidibe.

The new season is being hyped as a greatest-hits tribute reuniting fan-favorite characters.