Pink's 4-year-old son, Jameson, adorably tried to upstage his big sister, Willow, at her birthday party.

Over the weekend, Pink posted a video of a hilarious moment from the party she threw for Willow, who turned 10 on June 2.

In the clip, Willow is doing karaoke and singing Vance Joy's hit "Riptide," but while she's singing, Jameson, wearing striped pajamas, seems to be doing everything he can to take the spotlight off his sister.

He busts out some wild and crazy dance moves in the background of the clip, while holding a lollipop. "I threw Willow a party but no one told Jameson that," Pink captioned the clip, adding the hashtag "#thisfamilyisnuts."

PHOTO: Pink posted a video to her Instagram account of her son Jameson and daughter Willow.
@pink via Instagram
Pink posted a video to her Instagram account of her son Jameson and daughter Willow.

The singer also tagged Vance Joy and wrote, "our family loves you buddy!"

WATCH: Pink's son adorably tries to steal the show at his big sister's birthday party  

VIDEO: Pink's son adorably tries to steal the show at his big sister's birthday party
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The singer's son Jameson dances along to "Riptide" by Vance Joy at Willow's karaoke party.

At least Willow can take comfort in the fact that she got to perform an aerial routine with her mom during the recent Billboard Music Awards.