By Dave Quinn
April 15, 2018 at 01:10 PM EDT

They played two rival actresses competing for the same part on NBC’s cult favorite series Smash, but there was nothing but love between Katharine McPhee and Megan Hilty backstage at Broadway’s Waitress in New York City on Saturday night.

Hilty, 37 — a Tony-nominated veteran of the Great White Way with turns in shows like Wicked and 9 to 5 — swung by the Brooks Atkinson Theater, where McPhee is making her Broadway debut in the Sara Bareilles-penned musical.

The two former costars looked happy as can be, smiling and as they posed with one of the show’s prop pies.

On Smash — which premiered in 2012 and ran for two seasons — the stars were far less lovey-dovey as dueling divas hoping to land the lead role in a fictional Marilyn Monroe musical. The singers duetted on some of the show’s most memorable songs, like the iconic “Let Me Be Your Star” and the show’s title tune “Smash.”

Nowadays, Hilty lives in Los Angeles, balancing her career with motherhood — raising son Ronan Laine, 1, and daughter Viola Philomena, 3½, with singer-songwriter husband Brian Gallagher. She’s back the Big Apple for a handful of performances at the Café Carlyle (April 17-28).

McPhee, meanwhile, began limited her run in Waitress on April 10. The Scorpion actress and American Idol alum, 34, plays pregnant pie-maker Jenna Hunterson, who sets out to enter a pie contest in hopes of using the prize money to escape her unhappy marriage.

The musical is based on Adrienne Shelly’s 2007 movie of the same name, which starred Keri Russell as Jenna.

Starring in the show is a full-circle moment for McPhee.

“I’ve waited a long time to do Broadway mostly because I wanted it to be a show that I connected to,” she told PEOPLE in February. “I felt Waitress was just that: really well-suited for me.”

It helped that McPhee has a connection to Bareilles’ songs.

“Being a fan of Sara for all of these years, I always hoped she’d write a musical,” McPhee said. “And now to be starring in her show that she wrote music and lyrics to is a total dream.”

David Foster, who has been linked to McPhee, told PEOPLE Now earlier this month that he is rooting her on.

I think she’s going to kill it,” he said, admitting that he hadn’t yet seen her in action. “I think she’s going to be the new belle of Broadway.”

Dating rumors have followed the pair — who first met on the set of American Idol when McPhee was a contestant in 2006 — for months, but McPhee told PEOPLE in November that she had “zero desire” to address them.

“It’s great that they want to do that. I think it’s so amusing that people are amused by my love life,” she said. “Here’s how I look at it: I’m not doing anything wrong, so whether people think it’s true or false, I don’t, you know, there’s nothing bad happening in my life, so people can just say whatever they want.”

Tickets to Waitress can be purchased here.