Dylan Dreyer surprised with adorable birthday video from her sons

Dylan Dreyer’s boys are doing their part to make sure she has a memorable birthday.

While wearing matching T-shirts, Dylan’s sons Calvin, 5, and Oliver, 2, helped their mom celebrate turning 41 on Tuesday with a special video featuring them singing “Happy Birthday” to her.

Calvin leads the way in the performance, while he puts his fingers around his eyes and spiritedly moves his arms like a conductor. Oliver, meanwhile, does his best to keep up and busies himself by swinging a stuffed animal. Dylan’s other child, Rusty, 9 months, does not appear in the video.

“Happy 41 birthday!” Calvin says before the clip draws to a close. “It’s so weird that it’s Mom’s 41 birthday.”

"He did tell me, he's like, 'Forty-one. Wow, you're getting old.' Thanks, Cal," Dylan said on the 3rd hour of TODAY after seeing the clip and having a cake brought out to help her celebrate her big day.

The celebration continued throughout the day as Dylan later uploaded an Instagram slideshow that included a clip of Oliver playing his version of a birthday song on his toy trumpet. Calvin added to his brother's original tune by banging along on his miniature drum kit.

Then, it was Calvin's turn to create his own birthday lyrics in a second video. While hitting his drums, he sang, "Mommy, happy birthday, Mommy. You're the best mommy in the world."

Dylan's post also showed the mom of three enjoying a day on the golf course with husband Brian Fichera. The final three photos in the slideshow were pictures from her TODAY birthday celebration.

Calvin and Oliver certainly look like they are bursting with energy, which doesn’t come as too much of a surprise. Last week, Dylan peeled back the curtain on how hectic vacationing with three kids can be with a series of pictures of the boys in her bed.

“6:30am,” Dylan captioned the shots, along with the hashtags #vacation, #withkids and #wouldntchangeathing.

The love Dylan's kids have for her certainly goes both ways. In April, she posted a photo of her with all three children eating out at a restaurant, which can be a real test of any parent's patience.

“Ambitious? Yes. Worth it? Yes!!” she captioned the picture.

In his birthday post for his wife, Fichera also shared the photo of the two of them on a golf course.

"I’d love to post something about Dyls birthday but phones are frowned upon on the golf course and I honestly just want to get back to hanging out with my best friend. Happy birthday," he captioned the sweet Instagram picture.