Katharine McPhee and David Foster say their 35 years age gap 'keeps getting better' with time

LOS ANGELES, CALIFORNIA: Age is just a number for Katharine McPhee, 40, and David Foster, 75, who married in 2019. 

The couple have been celebrating a year of milestones together.

In March, Katharine celebrated her 40th birthday, followed by their fifth wedding anniversary in June. Most recently, on November 1, David celebrated his 75th birthday.

Katharine McPhee and David Foster say they 'don't dwell on their ages'

Record producer and composer, David Foster's big day was highlighted by a star-studded concert at the Hollywood Bowl titled: You're the Inspiration: David Foster.

The event featured performances by Andrea Bocelli, Michael Buble, Kristin Chenoweth, Charlie Puth, Jennifer Hudson, Tori Kelly, and Katharine McPhee.

The 'American Idol' alum and Foster, despite their 35-year age difference, remain unfazed by it.

"It's a big number. It's exciting," she told People about her husband's birthday, adding that they don't dwell on their ages.

"Honestly, I think that we're both very similar in this way," she said. "I welcomed my 40s, and David didn't have any conversations about, like, 'Oh, I can't believe I'm 75,' or I didn't say, like, 'Oh, I can't believe I'm 40. I'm really mourning that.'"

"We're kind of both cut from the same cloth. It's like we sort of just accept life as it comes, and we're not fighting getting older, because it just keeps getting better," McPhee told the outlet. 

David Foster says he's 'just groovin' on his 75th birthday

David Foster, the Grammy-winning musician, also shared his perspective on turning 75.

"She's fine, and I don't even think about it either. You know, I'm just groovin'," he told People at the event.

He acknowledged that the concert, combined with a fundraiser, made the whole experience "kind of a blur."

"So it hasn't caught up with me. I haven't really celebrated my birthday yet...," he said.

Foster continued, “And tonight, of course, is the concert. And I think maybe tomorrow I'll think that I've just turned 75.”

After the event, the composer took to social media to express his gratitude, saying, "I could not have asked for a better birthday. Thank you all for coming! And to all my incredible friends for making this happen."

Katharine McPhee and David Foster's journey together

Katharine McPhee and David Foster first crossed paths in 2006 when the latter was a guest mentor on season five of 'American Idol', where the singer finished as the runner-up to Taylor Hicks.

David also produced McPhee's first single after the show, when she was dating Nick Cokas, whom she married in 2008.

However, in 2013, McPhee was photographed with her 'Smash' director Michael Morris, leading to her filing for divorce from Cokas, which was finalized in 2016, according to Hello!

Foster and McPhee maintained a professional friendship and later rekindled their relationship.

In June 2018, the couple announced their engagement, and a year later, they got married in London.

They now share a three-year-old son, Rennie. Foster is also father to five daughters from previous relationships: Allison, 54, Amy, 51, Sara, 43, Erin, 42, and Jordan, 39.