While celeb moms like Madonna have been known to steal pieces from their daughter's closets, Fox has taken to transforming her wardrobe by borrowing T-shirts from hubby Brian Austin Green's 8-year-old son, Kassius.
And she's been doing it for years, according to the Daily Mail!
Earlier this month, the "Jonah Hex" star showed off her taut tummy -- and a taut top -- in Kassius's green "Voltron: Defender of the Universe" shirt.
She also bared her belly back in 2008, proving herself a force to be reckoned with in the boy's snug white "Star Wars" tee.
You gotta hand it to Fox -- she sure knows how to make being a sci-fi nerd look sexy. And if Kassius were smart, he'd put those Fox-worn shirts on eBay, pronto!