The lauded actress, 27, went to the movie’s premiere with her dad – having forgotten that she didn’t wear a bra for the film.
“It was an odd choice for me to have my entire family for this particular movie [premiere],” she told Seth Meyers on his US talkshow.
“It was a weird choice.”
She explained: “I wasn’t really wearing a bra a lot because I’m like Mother Earth.
“And my dad was sitting next to me, and I just forgot about that.
“And any time there would be a shot, my dad just go… [gasp].”
The superstar laughed that the scariest element of the whole film was “the outline of my nipple”.
Despite praise for Lawrence’s performance in Mother!, it is on course to be a big flop at the box office.
With just an $8 million projection in the US, it has also been given an unfortunate F grade by viewers polled by CinemaScore.
Mother! is out now.