Jake Bongiovi's proposal to Millie Bobby Brown almost ended in disaster when she dropped the ring "deep" into the ocean.
The 'Stranger Things' actress got engaged to the 21-year-old model-and-actor last April after over two years of dating and she has revealed he popped the question while they were on a diving trip - but she was so surprised, the jewellery fell off her finger and down into the water, prompting her new fiance to risk his life to retrieve it.
Appearing on 'The Tonight Show Starring Jimmy Fallon', Millie revealed: "This is too good of a story to not tell... Jake and I bonded over diving. We love diving, we got our diving licenses together.
"One day we were on vacation and he was like, 'Mil, you've got to be up at 8am we're going on a dive. And I was like, 8am? Dive like, what are we...?' "
Jake explained they were going to the "same spot" they "usually" went to, but Millie suggested they went "somewhere new" because she was bored.
She continued: "He's like, 'No, we have to go to this spot.' So we go under, and we're like many meters down, and he gives me like a shell. And I turn it over, and it's a a ring."
The pair looked at one another but couldn't hear what the other was saying because of their diving gear meaning the 'Enola Holmes' actress had to gesture her acceptance.
After they "freaked out" about being engaged, Jake then put the ring on Millie's finger, and then disaster struck.
She explained: "He puts the ring on my hand and as I go to show him, the ring falls off my finger, plummets like, so fast, it was like a a cinematic movie."
The diving instructor warned Jake he shouldn't go after the ring in case his brain "exploded" but he ignored the advice.
Millie continued: "Jake threw himself into - like, so deep. Like the diver was like, 'You can't do that. Your ears. Literally, your brain will explode.'
"He throws himself, he does a cinematic like grab, opens, and he saved the ring.
"I truly feel like it's a reflection of who he is, and I feel like we're always going to have each other's back. And if anyone drops the ball, we got it. So there we go."
Once they left the water, Jake proposed again - and revealed the jewellery he'd saved wasn't even the real thing because he had Millie's mother's own engagement band to present to her as her mum hadn't trusted him to take it in the water.
She said: "We got to the top, and he was like, 'Do you want to marry me?' And I was like, 'Oh, yeah. I mean, yeah that would be - you should probably ask me.'
"And then he was like, 'You know, I bought you this ring because your mom wouldn't let me take her ring.' Which is the one I'm wearing, this is my mum's ring. And my mum was like, 'Absolutely not, Jake. You're not taking my ring down there. I know you'll drop it,' and sure enough he did/
"She was right so when we got up on the boat, he was like, 'This is your mum's ring, and I got it from your parents.' And it was very magical. And his parents were there and we just looked so dishevelled coming out from a a dive.
"We were like, 'We're engaged, but also we have to tell you this crazy story that just happened.' "
Tagged in Jimmy Fallon Millie Bobby Brown