If you only know the Katharine McPhee love story from headlines, you probably think you know exactly how it goes. A legendary music producer meets a young singer on American Idol. He’s decades older. She’s the rising star. They get married, people roll their eyes at the 35-year age gap, and the internet moves on to the next scandal.
But honestly? Most of those assumptions are just flat-out wrong.
This isn't some whirlwind Hollywood hookup that happened overnight. It’s actually a twenty-year slow burn that involves a piano, a lot of "just friends" denials, and a level of family support that usually doesn't exist in "May-December" romances.
It All Started With a Whitney Houston Cover
The year was 2006. Katharine McPhee was 21, a contestant on Season 5 of American Idol with huge vocals and even bigger dreams. David Foster was the guest mentor. He wasn't just any mentor, though; he was the guy who literally co-wrote "I Have Nothing," the Whitney Houston classic Kat was set to perform.
Talk about pressure.
Foster was 56 at the time. To put that in perspective, he was already a 16-time Grammy winner while she was still trying to figure out how to handle a live television camera. During their first rehearsal, he told the cameras she had a "great, great future." It was professional. It was polite.
It was also the beginning of a friendship that would last through two of her relationships and several of his marriages.
The "Piano at the Wedding" Phase
Here’s the part that really trips people up: David Foster actually played the piano at Katharine’s first wedding. In 2008, when she married Nick Cokas, Foster was there as a guest and a collaborator.
They were close, but not "like that."
💡 You might also like: Pictures of Liv Tyler: Why Her Aesthetic Still Rules Our Feeds
For years, they were just industry peers who ran in the same circles. They showed up at the same charity galas. They worked on music together. Kat even joked later on that David would sometimes mention he had "feelings" when he was single, but she’d just laugh it off. She told him he was "insane" and way too old for her.
Life happened. Katharine went through a very public divorce from Cokas in 2016. David split from Yolanda Hadid (of Real Housewives fame) around the same time. Suddenly, for the first time in over a decade, both were single.
When the Katharine McPhee Love Story Actually Turned Romantic
The shift happened in May 2017. They were spotted at Nobu in Malibu, and the "insider sources" started whispering to every tabloid in town.
They played it cool for a long time. Kat told Health magazine they were just "very close friends" and that she’d known him since she was 21. She wasn't lying, but she wasn't giving up the whole truth either.
Then came the 2018 Met Gala.
Walking a red carpet together is basically the celebrity version of changing your Facebook status to "In a Relationship." They looked happy. More importantly, they looked like they didn't care what anyone thought about the 35-year difference between them.
David proposed later that summer on top of a mountain in Anacapri, Italy. Kat shared the news with a text screenshot that showed her sense of humor: "Thankfully he didn't push me off the cliff. He said it was one or the other."
The Wedding and the Critics
They tied the knot in June 2019 at the Church of Saint Yeghiche in London. It was an intimate affair with about 150 guests, including David's daughters.
That’s where the narrative usually gets messy. People love to judge. Critics called it a "mid-life crisis" for him and "gold-digging" for her. But if you look at David’s daughters—Erin, Sara, and Amy—they were the ones leading the charge in support of the marriage.
Erin Foster once joked on Instagram that she was "excited about my new stepmom," despite being older than Katharine herself. The family dynamic is surprisingly healthy. They’ve basically said that as long as their dad is happy and not being "a playboy," they’re all in.
Parenting in Your 70s
In February 2021, the couple welcomed their son, Rennie David Foster.
This added a whole new layer to the Katharine McPhee love story. David was 71 when Rennie was born. He already had five adult daughters, the eldest being 50 at the time.
David has been remarkably candid about being an "old" father. He’s admitted he won't be around when Rennie is 50, but he believes he can offer a level of wisdom and patience he didn't have when he was a younger, struggling producer.
Katharine, now 41 in 2026, has defended their parenting style too. She calls David "old-fashioned" but in a way that works for them. They’ve survived the "bikini-gate" controversy—where David praised her post-baby body and the internet lost its mind—and they seem stronger for it.
Why This Relationship Actually Works
So, what’s the secret? It’s probably the fact that they don't try to pretend the age gap doesn't exist.
- Shared Language: They are both musicians. They speak the same creative "tongue."
- Radical Honesty: Kat has mentioned in interviews that therapy is a huge part of their success. They talk through everything.
- Independence: Katharine has her own career (Broadway, Smash, Scorpion). She’s not just "David Foster’s wife."
- Humor: You have to be able to laugh when people mistake your husband for your father.
They still tour together. If you catch one of their "Intimate Evening" shows, you’ll see the chemistry is real. It’s not just a performance for the cameras.
Moving Forward: Lessons from the Fosters
The Katharine McPhee love story teaches us that timing is everything. If they had tried to date in 2006, it probably would have been a disaster. They needed those ten years of friendship to build a foundation that could withstand the inevitable public scrutiny.
If you’re looking for a takeaway, it’s this: ignore the "shoulds."
People told Kat she was throwing her career away. People told David he was being ridiculous. Instead of listening, they built a life that includes a toddler, a successful joint tour, and a blended family that actually gets along.
Next Steps for Fans:
If you want to see the dynamic for yourself, check out their 2023 Christmas album or look for their 2026 tour dates. They often share "behind the scenes" clips on TikTok where Kat continues to troll the haters with iconic soundbites. Honestly, it’s the best way to handle the noise. Just keep singing and let the skeptics wonder how you're still so happy.