That intuition led the writer-actor to process the news through penning a one-man musical with his two childhood friends based on his real-life extraordinary genetic discovery.
Another aspect of the personal bombshell was the fact that the only child actually had more than 35 half-siblings.
"I've met people who have had similar experiences and when they don't have an outlet, whatever it may be, to wrangle it and make sense of it and own it, it can remain a big obstacle, something you never get past," he said. "I think it was my way of getting through it."
After successful runs at the Toronto and Edinburgh Fringe Festivals, a showcase in New York, and performances in other Canadian cities, "Our Little Secret: A True New Musical" is heading to the Off-Mirvish stage, giving the Toronto-born performer a special homecoming.
"It's everything. It's like the Olympics," he said of the show hitting the CAA Theatre for a nearly three-week run, beginning Nov. 3.
For Tomaschoff, the last four years have been a whirlwind.
He had a typical childhood and said he never had any reason to suspect his parents were keeping anything — let alone an identity-shaking secret — from him. But as detailed in a lengthy 2023 Toronto Life feature, when he was 31, a woman he was dating, who is now his fiancée, told him about direct-to-consumer genetic test kits. On a whim, he ordered one. When he told his mom about the impending DNA test, the series of life-shifting events unfolded.
Unable to conceive naturally, Tomaschoff's parents turned to sperm donation and decided to tell only a few family members. Tomaschoff said it wasn't in his nature to lash out at his parents. Intellectually, he said, he understood their reasons for not telling him.
"That was the general guidance at the time; it made sense," he said. "There wasn't as much of a support structure. There's a lot of shame around this type of thing, so I was never there being like, 'How could you do this?' I know why they did it."
After taking the DNA test, Tomaschoff connected with other people who were conceived via the same sperm donor. The man died before Tomaschoff learned of their relation, but he has since grown close to some of his half-siblings, he said.
While his parents wanted their son to keep the truth under wraps, Tomaschoff refused. Before learning about his true backstory, the 35-year-old artist had been living in Los Angeles, struggling to land auditions and feeling "creatively adrift" after wrapping up an independent feature film project, he said.
"I had never had such a stroke of inspiration about any other project I've done in my life" he said.
After receiving a slot in the 2023 Toronto Fringe Festival, Tomaschoff wrote the show with his best friends, composer Ryan Peters and producer Russell Citron, whom he had met in high school and, fittingly, bonded with over a love of musical theatre.
The show, then called "Our Little Secret: The 23andMe Musical," sold out all its performances and earned awards, including the Patron’s Pick and Best of Fringe.
Tomaschoff has since performed it at the Edinburgh Fringe in 2024 and later in Montreal. The show is currently playing at Edmonton's Citadel Theatre until Oct. 25. Ahead of its return to the Toronto stage, Tomaschoff said the show's rise has been "very amazing and humbling."
"Our Little Secret" has evolved since its original conception. Initially, Tomaschoff said, it focused on the fun, joyful and wow moments, but after receiving constructive feedback that it lacked emotional, vulnerable notes, he said the show now better balances the highs and lows of that time period.
"It would be unsatisfying for the general audience to see a show that's just kind of all happy. It certainly wouldn't be true if it was all sad," he said. "It's trying to have everything in there that was a key step along the way, whether it was a difficult moment or overcoming that."
The new production is directed by veteran stage performer Adam Pascal, best known for his role in the original Broadway and West End productions of "Rent." In "Our Little Secret," Tomaschoff speaks directly to the audience — referred to as breaking the fourth wall — and plays multiple roles, including his parents, Gideon Tomaschoff and Sylvie Leone-Tomaschoff.
When he was creating the musical, he kept his folks in the dark about its contents, a move he described as "my little payback." But when his parents first saw it performed, they really liked it, he said. With every new iteration of the script, he strives to represent them authentically, while not shying away from difficult moments.
"It's a negotiation, but we always strive to arrive at consensus around each new version of the script, which I think it must be the first musical in history where the parents essentially have an editorial role in the writing of it," Tomaschoff said. "But it's another way that we kind of keep each other honest."
Tomaschoff's story is specific, but he said the show deals with universal themes such as identity and family crisis. He wants audiences of all ages to walk out of the show inspired to embrace honesty in their relationships.
While he's had years to process the truth, Tomaschoff said during performances, he can still tap into the initial moment of shock.
"I think I will be able to forever because it was just such a life-changing moment."
This report by The Canadian Press was first published Oct. 21, 2026.
By Kaitlyn McGrath | Copyright 2026, The Canadian Press. All rights reserved.
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