Jake Bongiovi’s underwater proposal to Millie Bobby Brown nearly went very south.

Brown shared the “crazy story” with Jimmy Fallon on “The Tonight Show” Thursday. The “Stranger Things” star announced her engagement to Bongiovi, the son of musician Jon Bon Jovi, in April last year.

Brown said she and Bongiovi had bonded over diving and got their diving licenses together, prompting his decision to propose to her under the sea.

“We were on vacation and he was like ‘Mill, you gotta be up at 8 a.m., we’re going on a dive,’” she said.

“So we go under, and we’re like many meters down, and he ... gives me like a shell, and I like turn it over, and it’s a ring,” she went on.

Unable to speak underwater, Brown said she struggled to communicate that she was saying yes. He put the ring on her finger, and she tried to show it to him on her hand.

“As I go to show him, the ring falls off my finger. Plummets, like so fast. It was like a cinematic movie,” she continued.

She said Bongiovi “threw himself” into the deep in pursuit.

“The diver was like, ‘You can’t do that,’ like your ears ― you literally, your brain will explode,” she said.

“He does a cinematic, like, grab, opens, and he saved the ring,” she added.

She said she felt the moment was a reflection of who he is, “and I feel like we’re always gonna have each other’s back, and if anyone drops the ball, we got it.”

When they surfaced, Brown said, her fiancé explained that he had asked for her mom’s ring, but Brown’s mom had said “absolutely not,” predicting he would drop it.

He gave her that ring above the surface.

Watch the interview below.