Katharine McPhee Poses In A Bikini With Soon-To-Be Stepdaughter Sara Foster And Gets Roasted

Katharine McPhee must be getting used to being trolled by her fiance David Foster's daughters. The 34-year-old Smash star, who got engaged to the 69-year-old Grammy-winning music man during a trip to Capri in July, posed in a bikini next to her future stepdaughter, Sara Foster, as the clan vacationed at the Four Seasons Resort Lanai in Hawaii over the holidays. But Sara couldn't resist posting a cheeky caption to the sexy shot.

In the photo, which you can see below, Katharine McPhee is wearing a black and white patterned bikini with cutouts while Sara Foster is wearing a sexy floral patterned two-piece. Katharine is leaning on Sara's shoulder and smiling at the camera as she flashes her massive diamond engagement ring.

While both women rocked their bikinis, Sara, 37, couldn't help but tease her dad's young fiancee about her killer beach body. Foster's daughter captioned the pic with, "When your mom refuses to dress age appropriately."

According to Page Six, Katharine McPhee responded to the post by writing, "I can't even think of a good response," and Sara Foster fired back with, "As long as you keep looking this good in a bikini, I will be writing captions like these."

You can see Sara Foster's cheeky Instagram post with Katharine McPhee below.

Katharine McPhee's sexy bikini snap comes less than a week after she was trolled by one of her other future stepdaughters, Erin Foster. As previously reported by the Inquisitr, last week Erin, 36, roasted her stepmom-to-be after she posted a photo of herself sunbathing in a bright yellow bikini.

After Erin commented, "Grandma!!!! Wtf I don't want to be next to you at the pool," McPhee responded by joking that "grandma carries it in the back" and she added that her cellulite is all there when she stands up.

It's clear that Katharine McPhee has a friendly relationship with her future stepdaughters. In July, when McPhee and Foster announced their engagement on social media, the music producer's daughters hit the comments section to post their reactions to their father's engagement to a woman half his age.

The Daily Mail posted a screenshot of Foster's daughters' comments on his Instagram photo. Erin Foster wrote, "'Mommmyyy" along with three red heart emojis, while Sara later joked, "Out of the country. What did I miss?"

Foster's daughter Sara later told Us Weekly that she and her sisters "totally approve" of their famous dad's fiancee, who will be his fifth bride.

"He's happy in this relationship and it bothers me that anybody would say anything negative about it," Sara Foster said. "[Katharine] is a grown a** woman. She's not 20, she's turning 34. And my dad is very young. He's like a very young, young dad/grandpa."

In addition to Sara and Erin Foster, David Foster is father to daughters Amy, Jordan, and Allison Foster. Only Jordan Foster is younger than Katharine McPhee.