Jackson and Culkin headed to a West Hollywood tattoo parlor on Saturday to get matching ink.
They decided to get tiny spoons tattooed onto their arms.
The godfather-goddaughter duo didn't explain the meaning behind the twinning tats.
But they'll forever have the kitchen utensil to symbolize their bond.
The spoon is just one of Jackson's 50+ tattoos.
She's only 19 years old, but Jackson already has over 50 tattoos (nine of which are dedicated to her late father, Michael Jackson).
Near her collarbone, Jackson inked "FAITH, TRUST AND PIXIE DUST" as a permanent tribute to Michael, who liked to imagine himself as Peter Pan and his only daughter as Tinker Bell.
"He's brought me nothing but joy," she said, explaining her tattoos to Rolling Stone earlier this year.
"So why not have constant reminders of joy?"