Katharine McPhee and David Foster send clear message to critics of their 34-year age difference

Katharine McPhee and David Foster don't care what you think about their relationship.

The former "American Idol" runner-up recently performed on Vacaya's LGBTQ+ cruise in Provincetown, Massachusetts, where she sang a song from "Wicked" with fellow Broadway icon Kristin Chenoweth and brought her own husband, David Foster, up to the stage.

SEE ALSO: Inside David Foster and Katharine McPhee's fairytale wedding

Page Six reports that when Foster, 69, joined his wife onstage, he took the opportunity to send a clear message to critics of their 34-year age difference.

See photos of David Foster and Katharine McPhee together:

"I don't know if you noticed or not, but there's a bit of an age difference between the two of us," the music industry legend reportedly said. "But on this cruise, nobody gives a sh-t!"

The next night, during another performance on the ship, McPhee, 35, chimed in when Foster repeated the comment -- which was clearly a hit with the audience -- saying, "Go f--k yourself!"

SEE ALSO: Katharine McPhee and David Foster pack on the PDA during Italian honeymoon

The unapologetic couple has had quite the milestone summer, having tied the knot in London on June 28, where they were joined by about 100 family and friends. McPhee and Foster started dating in the spring of 2017, though they initially met when McPhee was on season five of "American Idol" back in 2006.

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