We smell a new squad in our midst!
However, it appears the epic collaborative performance gave an even cooler gift in the form of new best friends, Blue Ivy Carter and Apple Martin.
For the snap, the Oscar winner wrote:
This is becoming a tradition for them!
But it wasn't just the four of them! Gwen's parents Dennis and Patti Stefani were also in attendance, helping out with the kids.
Gavin's holiday weekend was cut short though as he went back on the road on Saturday to tour with his band Bush.
[Image via Ramey Pix.]