The idea of the gender reveal cake is simple: at one of your ultrasound scans, you get the specialist to write down the gender of your unborn baby on a piece of paper, which is then placed in a sealed envelope. You take it to a baker, who then bakes a cake which has blue or pink icing or coloured batter on the inside. You cut the cake at your reveal party and voilà, your baby's gender is revealed in a tasteful (and tasty) way.
But for Natalie and Ben Bell, of Canonsburg, Pennsylvania, it wasn't that simple at all.
In a video shared online last month, the Bells are seen cutting their cake in front of excited family and friends. When the icing appears to be pink, the room erupts into cheers.
"We cut the cake and it was pink icing and we were so excited – you can tell by all the screaming that everyone was thrilled," Natalie told ABC News.
But when Natalie took a photo of the cake to share on Facebook she had an inkling something wasn't quite right. "I noticed when I took the picture that the icing of the cake was kind of light and looked whiteish, so you might not able to tell [the gender right]," she said.
To check that everything had gone to plan, the couple opened the extra envelope they'd taken home themselves. It said "Boy".
They then opened the card they'd given the baker. Yep, it said it too: "Boy". The icing was wrong.
"It didn't make any sense," Ben told ABC News. "Natalie almost passed out from being overwhelmed with the news. She was just in complete shock. Everybody was so confused so I had to yell, 'It's a boy,' because nobody understood what was going on."
To the credit of the party-goers, the cheer for the updated news was just as loud.
"Maybe it's twins!" one party guest joked.
When the couple rang the bakery, staff were also shocked and confused. They immediately offered a refund for the faulty cake.
"This is stuff people joke about! It's made for a really interesting, hilarious story. I feel like I'm finally recovering from the shock of it all," Natalie said.
"I'm not quite laughing about it yet, but someday I think I will be. It's definitely a memorable experience to have for our first child."
The baby boy is due in March.