By Alicia Lee, CNN

(CNN) -- Reese Witherspoon is proving once again that she's not a regular mom, she's a cool mom.

Her 16-year-old son Deacon Phillippe dropped his first single, "Long Run," featuring Nina Nesbitt last week. And being a proud mom, Witherspoon showed off her son's latest accomplishment on Saturday not with a simple post on Facebook or Instagram, but through the medium of choice for Gen Z -- a TikTok dance.

The TikTok video shows Witherspoon having a lightbulb moment after bopping her head to "Long Run" as Phillippe plays the tune on his phone.

"Deacon, I should make up a TikTok dance to this song," the 44-year-old actress says. Based on the fact that Phillippe taught Witherspoon what TikTok was and how to use it just a couple months ago, this is major progress.

Still, Phillippe doesn't seem too excited about the idea as he covers his eyes and lets out a "No, mom, no!"

Witherspoon carries on in true mom mode, dancing and grooving to the music.

But despite his embarrassment, Phillippe showed that he appreciated her support by commenting on the post with "Hahahahah I love you."

Witherspoon's video has racked up millions of views on both TikTok and Instagram and other celebrities are chiming in with their support for Phillippe's single.

"We mortify them, but it's from pure love! Way to go Deacon!" actress Gwyneth Paltrow commented.

"Great song and DANCE," actress Octavia Spencer wrote.

Earlier on Friday, when the song was released, Witherspoon proved that she was her son's No. 1 fan by writing on Instagram that it is "the perfect summer bop with a sick beat and dope drops (is that what the kids say?!)"

In his own post, dad Ryan Phillippe wrote, "Stream it nonstop for me. So proud of you @deaconphillippe."