Scarlett Johansson is hoping to keep her past a secret from her kids.

During an appearance on The Drew Barrymore Show Wednesday, the 37-year-old actress answered questions for Drew Barrymore’s “The Final 5” segment. The Sing star — who is mom to 7-year-old daughter Rose Dorothy and 7-month-old son Cosmo — revealed the one thing she hopes her children never know about her.

“My daughter may have asked me this before,” Johansson admitted. “I used to smoke when I was younger and I’m so ashamed. I just don’t want her to ever think that I ever thought it was cool ’cause she can never, ever, ever smoke.”

” ‘Cause that’s what you do. You forbid your kids from doing things and then they don’t do them,” she quipped. “So yeah, I just hope she never figures that out.”

The Black Widow star might have some trouble keeping her previous smoking habits a secret from her little girl because she recently told InStyle that Rose is currently at an age where she is curious about everything.

“Why are you tweezing your eyebrows? Why are you curling your lashes? What’s a tampon? What’s it for?” said Johansson, imitating her daughter.

“She asked me why my underwear went up my ʙuтт crack, and I had to try to explain what a panty line was,” she recalled. “I was like, ”cause you don’t want a line in your pants,’ and she was like ‘Why?’ And I was like, ”cause then you could see my underwear,’ and she was like ‘But you are wearing underwear.’ Like I know, it’s weird.”

Though Rose is curious about many things, Johansson admitted in December that her daughter has yet to show much interest in her new baby brother.

“She has a lot going on in her life. She’s got a very active social calendar, so she’s not as interested in the baby as, I don’t know, let’s say, like, any other thing really?” the star said in a virtual interview with Jimmy Fallon on an episode of The Tonight Show.

Johansson also revealed that Rose is finding her mom “a little” embarrᴀssing nowadays

“I do a little dance when the school bus pulls up, and she doesn’t like that,” Johansson confessed to Fallon at the time. “Of course, then I exaggerate it even further.”