Kelsey Grammer and Bebe Neuwirth Reunite in Frasier First Look: 'A Great Time Visiting Lilith and Frasier' (Exclusive)

Anytime Kelsey Grammer and Bebe Neuwirth step back into the iconic roles of Frasier Crane and Lilith Sternin, they deliver a comical tour de force. Sparks fly. Sharp barbs are traded. Antics ensue.

Expect nothing less from Grammer and Neuwirth, who reprise their roles as the bougie psychiatrists in Frasier's newest episode "Freddy's Birthday," airing Thursday on Paramount+. In it, Frasier and Lilith begrudgingly reunite for their son Freddy's (Jack Cutmore-Scott) birthday party.

For Grammer and Neuwirth, it's been nearly two decades since they appeared onscreen together, when the episode "Guns N' Neuroses" aired during the eleventh and final season of NBC's Frasier. But for Neuwirth, stepping back into the delightfully frosty role of Lilith after all this time was a joy.

“It’s always a pleasure and a great time visiting Lilith and Frasier," Neuwirth exclusively tells PEOPLE. "So fun to be back in that wonderful character.”

In PEOPLE's exclusive debut of the reunion teaser, Frasier and his longtime pal Alan (Nicholas Lyndhurst) enter one of their regular hangouts. While debating the merits of a modern production of the Italian opera Turandot — "They changed the Imperial Palace to a Costco in Chicopee!" Frasier complains — Frasier spies Freddy, who is sharing a drink with a mystery woman at a table nearby.

"That's odd. Frederick told me he had plans this evening when I invited him to the opera," Frasier says. "I didn't realize it was a date."

"Oh, I was a back-up choice, was I?" Alan retorts. "Fine. I'll just write that in our friendship ledger — in red."

"The sly dog, he clearly traded up," Frasier continues. "Ditched his old man for an evening with an enchanting ingenue. Let's go say 'hello.'"

Freddy's date, it turns out, is none other than Lilith. "Frederick, you old dog. Who is this lovely... serpent??" Frasier asks, nonplussed.

"Hello, Frasier," she says.

"Lilith. Dear god. Who looked in a mirror and said your name three times?" he replies.

"Frasier, I almost didn't recognize you. I'm used to seeing you wedged between commercials for injury attorneys and walk-in tubs," Lilith deadpans. "I'm just joking. I've never seen your television show."

Frasier fires back with a clever dig of his own. "Good to see you, but if you're here, then who's minding the children you've lured to your gingerbread house?" he says.

"Okay, you crazy kids," Freddy says uncomfortably as he sips his beer and the clip ends.

In Paramount+'s revival of Frasier, the acclaimed psychiatrist moves from Seattle back to Boston and takes a teaching job to be closer to his grown-up son Freddy. For Lilith, it's hardly her first time in Boston, either. Frasier and the icy doctor share a long and complicated history spanning nearly 30 years that had its start in the city that "never gets old."

The two first met on a rocky date during the fourth season of NBC's popular sitcom Cheers in the episode "Second Time Around." Being hugely unimpressed when Frasier takes her to Cheers for drinks, she all but leaps at the chance to return to the hospital when her pager goes off.

"With any luck, it'll be one of my manic depressives, and the evening will take an upturn," she says.

It's not until the season 5 episode "Abnormal Psychology," after the two find themselves paired on the talk show Psychology This Week in what becomes a laughable, sexually suggestive debate that Frasier and Lilith finally cave to their carnal desires for each other.

Once Lilith lets down her hair at Cheers, the good doctor is triggered. "I'm going to kiss you," Frasier says. "I'm going to kiss you hard, and I'm going to kiss you long. But make no mistake about it. I am going to kiss you."

The couple eventually tie the knot, and after going into labor at Cheers, Lilith gives birth to Freddy, or Frederick, in the backseat of a taxi during the season 8 episode "The Stork Brings a Crane."

But their marriage isn't meant to last. During the episode "Teaching with the Enemy" in Cheers' eleventh and final season, Lilith confesses to Frasier that in a "moment of extreme weakness" she cheated on him with one of her colleagues, Dr. Louis Pascal.

Although Frasier forgives Lilith, the couple divorce sometime between Frasier's move from Boston to Seattle, setting the stage for many memorable scenes between the pair, who now go back and forth between loving and loathing each other.

Lilith first reemerges on NBC's Frasier in the season 1 episode "The Show Where Lilith Comes Back." While Frasier is giving advice on his radio show to Hank, a caller who is grappling with his weight, Roz (Peri Gilpin) informs him there is "someone on line 1 who disagrees" with Frasier's counsel.

The exes reconnect later on and sleep together, and while Frasier confesses to Lilith he feels it was a "mistake," he adds over breakfast the morning after that she was always "the most exciting lover" he'd ever had.

In the season 10 episode "Lilith Needs a Favor," Lilith calls upon Frasier for, well, a favor: a sample of his sperm so she can "complete her life" and give Freddy a sibling. Frasier is not-so-secretly hoping for a roll in the hay, but Lilith argues that going to a doctor's office and freezing his sperm is the more practical route because otherwise, she'd have to fly back and forth to Seattle when she's ovulating.

At the fertility clinic, Frasier expresses doubts. Their second child might inherit all their "flaws" instead of their "strengths." "We could create a real nightmare," he adds, before he realizes that helping Lilith in this situation doesn't "feel right" and changes his mind.

Lilith's most recent appearance in Frasier's life was on "Guns N' Neuroses' in season 11 of NBC's Frasier. While in town for a one-day conference, Lilith is unwittingly "fixed" up on a blind date with Frasier by one of her colleagues. The two exes have a drink in her hotel room, cancel on their dates, never realizing the truth, and wind up successfully counseling a bickering couple in the next room over.

Frasier and Lilith fall asleep on the couch, and as they hurriedly get ready the next morning — Lilith to catch her flight in an hour-and-a-half, Frasier to make his way home — they confess to each other that dinner together the night before was "lovely." In that moment, Frasier allows himself to wonder what might have been if they'd never met.

"We're exactly the kind of people that somebody might set up on a blind date," he says with a chuckle, adding, "What would we think of each other if we were just meeting now for the first time?"

"But if we hadn't met, we'd be different people now," she contends, before the two go back and forth about how life would be different.

"We do have our baggage don't we?" he says at the door. "But then sometimes that's what makes the trip so interesting."

"With one hand the past moves forward, and with the other it holds us back," Lilith offers.

They embrace and wish the other "good-bye," before exchanging long glances each other's way and the credits roll.

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Frasier airs Thursdays on Paramount+.