Katharine McPhee, 37, and David Foster, 71, leave for the FIRST TIME with their son Rennie

Katharine McPhee and her husband David Foster, 71, were first seen with their newborn son Rennie on Thursday, while enjoying brunch in Beverly Hills.

The family dined outdoors at the stylish Maybourne Hotel with a select group of friends in celebration of McPhee’s 37th birthday.

Katharine, who welcomed her first child with David in late February, looked like a loving mother as she cuddled Rennie lovingly in her arms at the designated dining table.

Clearly in love, Katharine pressed her son’s head against her cheek before giving him a few kisses.

The tiny newborn looked sweet in a bright white jumpsuit and struggled in his mother’s arms as she continued to pet him.

Katharine and David were seen arriving at the luxury establishment with Rennie safely tucked away in a padded baby seat, which Katharine easily held.

Actress Waitress looked ready for spring in a colorful floral mini dress with a deep neckline that allowed her to show off her plain neckline.

Due to the windy weather, Katharine adorned her outfit with an ivory-colored cardigan that hung right after her dress.

She had a myriad of gold chains around her neck and a pair of gold rings around her ears.

McPhee’s dark hair was parted in the middle and combed into a low, chic ponytail and displayed an appearance of natural, flushed makeup.

While Katharine took control of the baby stroller, David carried his belongings in a blue Givenchy bag that he held in one hand.

The 71-year-old musician transformed himself into an elegant figure to celebrate his wife’s birthday in a pair of worn-out jeans and a light blue button-down shirt.

Foster braved the unusually cold SoCal climate with a navy blue jacket.

After enjoying the delicious brunch with friends, the couple fled the establishment and headed for the black SUV.

Rennie looked incredibly comfortable in her stroller, while she was wrapped in a white and gray baby blanket.

Following the COVID-19 safety protocols, McPhee and Foster made sure to wear face masks.

Katharine effortlessly placed the newborn in the back seat of the car, while David sat in the driver’s seat.

Katharine’s representative announced the famous announcement of Rennie’s birth in late February, telling People: ‘Mom, Dad and son are all doing wonderfully.’

Rennie is Katharine’s firstborn, but David also has five daughters – four of whom are older than the current stepmother.

McPhee finally revealed his newborn son’s name while making a remote appearance on Today earlier this month.

‘My husband is probably going to kill me for saying that, but his name is Rennie David Foster,’ she said.

She explained to the presenter of Today that she and David ‘had some names [picked out], but my husband was in a text string with his sisters and one of his sisters suggested an old surname. ‘

The Smash star continued: ‘It was your great-grandfather’s name, your great-uncle’s name, so it has a long history in your family.’

Then, after the baby was born, ‘My husband said,’ Hi, Ren Foster ‘, and then we said,’ It’s a good name. It’s a strong name. ‘

Katharine was previously married to Nick Cokas, 55, but they broke up after she was photographed kissing her dashing Smash director, Michael Morris.

She became involved with David in 2017 and they were married two years later in London, where she had played in a West End production of Waitress.

Katharine met David in 2006, when she was a competitor on American Idol and he was a guest mentor.

The Smash actress is David’s fifth wife – her most recent predecessor was Gigi and Bella Hadid’s mother, Yolanda, who used to be a real Beverly Hills housewife.