Okay ... so they're temporary tattoos, but still!

Kate Hudson's 8-year-old son Ryder hit the Santa Monica Pier with dad Chris Robinson, stepmom Allison Bridges and little sister Cheyenne Genevieve ... and the little boy was showing off some temporary ink on his arm and behind his ear.

We have a feeling Ryder will be going a bit more permanent when he gets older. Like father, like son!