Drew Barrymore‘s all for leaving the underwear in the dresser drawer … but she says she’s gotta keep her head on a swivel — ’cause her daughter’s got a penchant for pantsing.

The actress/talk show host revealed one of her daughters loves to pull her pants down around the house as a prank … on account of DB walking around without undies on all the time.

Drew was sitting with her cohost Ross Mathews, ‘SNL’ star Chloe Fineman and singer Boy George when the question of going commando came up … and Drew was first to admit she’s all for feeling free down there.

And, DB’s saying she doesn’t just do it if she hasn’t gotten to the laundry in a bit … saying she actually enjoys dressing sans underwear — a choice so well-known in her household it leads to the pantsing pranks.

Barrymore was quick to add her daughter is only doing it as a joke, and she said she’s made it clear to her kid it’s only an around-the-house kinda gag — nothing for mixed company or the outside world.

Drew’s got 2 kids with her ex-husband Will Kopelman BTW … 11-year-old Oliveand 9-year-old Frankie — but, she didn’t reveal which one’s the little prankster.

She’s not even the first celeb this week to cop to domestic nudity — Bradley Cooper revealed he’s always fully exposed at home, and even chats with his daughter while he’s on the toilet and she’s in the tub.

Anyhoo, watch your back, Drew — or your backside might end up hanging out for all to see!