Daddy knows how to get down!
"I can't think of a better way to celebrate a 4th birthday," Duhamel posted on Instagram along with the video. "Happy birthday Axlito!"
The Black Eyed Peas singer also celebrated her son's big day by posting some precious pictures on Twitter and Instagram and sending him lots of emoji-filled love.
Hopefully, year four will be easier for the parents than year three.
The Transformers actor also shared some of his son's adorable antics on the show.
"He's all about spooky stories, taking sticks from the park and turning them into stuff," he said. "I mean, we literally have a pile of sticks at our house. We could have a giant bonfire at any moment."
DeGeneres also asked Duhamel about how his parenting style differs from Fergie's.
"We make a lot of questionable parenting decisions, I think," he said. "I have no idea what I'm doing half the time. She's definitely more evolved than I am and more patient. But I feel like, having a kid when I was 40 years old is much different than having a kid at 22. I'm a little bit more mature than I was then! I'm just doing the best I can and trying not to screw him up for life."
After years of being together, the married couple still makes time for romance. Although, at the 2017 Billboard Music Awards, Duhamel told E! News' Sibley Scoles that date night is a little different now that they're parents.
"What does date night look like now?" Duhamel asked. "It's dinners. It's trying to get away for a quick weekend, maybe. Things like that. More chill."
Sounds like a good evening to us.