Katharine McPhee Wishes Son Rennie A Happy Birthday: 'I LOVE YOU'

Katharine McPhee celebrates her son's birthday on social media!

The "Scorpion" star, 37, shared a heartwarming tribute to her son Rennie David on his 1st birthday. McPhee took to Instagram today to celebrate her one and only child’s special day, adding several pics from his Safar-themed birthday bash. See them below.

"Happy Birthday to our cutie baldie baby who turns 1 today!" she began.

McPhee also reflected on motherhood.

"Where does the time go? I know you’ve heard this before but being a mommy is the greatest fricken thing in the world," she noted. "Here are some highlights from his 1st party. I LOVE YOU SO MUCH RENNIE!!!!"

Within an hour of going live on her Instagram feed, the post has earned more than 11,300 likes and upward of 160 messages. McPhee's avid fans flocked to the comments section and wrote birthday wishes for her little boy.

"Happy birthday beautiful dude !!!!! ❤️❤️❤️❤️❤️❤️❤️❤️" singer Michael Bublé wrote.

"A perfect party. A perfect day. A perfect Mom. A perfect Rennie!!!!! Happy birthday sweet boy!!!!" added another follower.

"Happy birthday to Rennie, may God bless him and may he grow more every day. ?? I can't believe he's turning 1!! ? He has no idea how lucky he is to have such wonderful parents," a third user commented.

"Happy Birthday to your beautiful baby boy, Rennie!!! Being a mommy looks wonderful on you Kat," quipped the fourth fan.

McPhee welcomed her bundle of joy in February 2021 with husband David Foster, 72.

At the time, a rep confirmed the news of the baby's birth.

"Katharine McPhee and David Foster have welcomed a healthy baby boy," the rep told People. "Mom, Dad and son are all doing wonderfully."

The couple married in June 2019. They met in 2006 when the Grammy winner mentored McPhee and other contestants on season 5 of "American Idol."

Foster is already a dad to daughters Sara, 40, Erin, 38, and Jordan, 34, who he shares with ex-wife Rebecca Dyer, and daughters Allison, 50, and Amy, 47, from past relationships.

In April, McPhee talked about being a new mom during a recent appearance on "The Kelly Clarkson Show."

"I'm a little bit tired here and there, but I find times to nap and he's such a good little baby,” she told host Kelly Clarkson. "I'm so in love. ... It's my greatest job I'll ever have."

Clarkson also shared, "The hardest thing for me is when they're so freaking cute and you love them so much, but they're doing something that's naughty and you're like, ‘Nope, you will not twist me around your finger!'"

McPhee, however, admitted that it’s hard for her to imagine those days ahead when looking into her baby's adoring eyes.

"My girlfriend ... was like, ‘Oh, can you even imagine that you're going to have to get mad at him one day?’" the singer recalled. “And I'm like, ‘No, he's so sweet right now. I can't imagine."'