When Sarah Benibo and her family reunited for a Thanksgiving trip last November, she thought it would be the perfect time to break the news to her parents that she and her husband were expecting again.
Benibo told "Good Morning America" it was her sister Sophia Stephens who had the funny idea to play a "bun in the oven" prank on their parents Dorretta and Ron Stephens as they all gathered in an Airbnb rental in California.
"Initially, I was like, 'This is so cliche. This is so typical. They're gonna know immediately.' But my sister was like, 'No, we should just do it.' So we ordered the Instacart groceries and once my mom and dad arrived, I put my son to bed and then we started the whole prank at that point," Benibo recalled.
Sophia Stephens captured the prank on camera and after Benibo shared the video on Instagram Monday, it quickly went viral.
In the video, the sisters alert their parents that there appears to be an unexpected problem in their Airbnb: Someone has left a sole hamburger bun in the rental house's kitchen oven. As they talk their parents through the idiomatic expression, it slowly dawns on mom Dorretta Stephens what they're actually discussing.
"I'm thinking nothing because as soon as she opened the oven, I'm thinking, 'Who does this? Who leaves a bun in the oven?' No clue whatsoever," Dorretta Stephens recalled to "GMA."
MORE: Sweet best friend pregnancy reveal has us crying happy tearsRon Stephens said he was just as stumped before the happy news sunk in.
"I was like, 'What is still going on?' I couldn't put the dots together and I felt a little bit embarrassed because everybody was like, rejoicing," he recalled. "Later on, they said, 'It's a baby!' Then, 'Oh, I've got it!' So, the bun in the oven didn't work with me. I didn't know what was going on."
Benibo said her parents really fell for it, as she typically doesn't pull pranks on people.
"That's not really our thing, but for babies, it's just such a celebratory time. It's just such a happy moment for everybody involved, especially considering I couldn't get pregnant for the first couple of years of my marriage," she said.
MORE: Grandmothers scream in excitement over pregnancy newsAfter her secret was revealed, Benibo and her family celebrated. It wasn't until this week that she decided to share the hilarious throwback video in honor of her mom's birthday, which was this past Monday.
"I kind of just forgot about the video. We came back from California, it's Christmas now, you know, we just moved on. And then once my mom's birthday was coming up, I was like, 'Oh, I need to post something, to just show her personality,'" Benibo explained.
"I knew that she would get a kick out of it, and it's her birthday," she added.
Now, the expectant mom and her husband Bio Dienye Benibo are getting ready to welcome their second child, and the Stephenses said they can't wait to meet their third grandchild.
"Oh my goodness, yes. And it's a little girl. We're all going to spoil her," Dorretta Stephens said.
