When it comes to talking about their babies, Ryan Reynolds and Blake Lively like to keep things to themselves.
When they had their first child (daughter James), they kept the news of her name a secret for quite some time.
And, since welcoming their second baby in September this year, they have yet to even confirm the baby's gender.
That was until Ryan went on Conan this week and confessed there's "a lot of oestrogen" in his house at the moment. (He then said, "It feels like an American Girl [doll] took a s*** on my life," which only makes us love him more.
While we can't be sure if he really did spill the couple's secret, it seems likely. Especially considering Blake posted on Instagram afterwards that Ryan "got himself into huge trouble" on the show. (He 'made up' for it, apparently, by bringing his wife milk and cookies. Bless.)
While most couples announce their baby's gender after the birth, there are those who accidentally reveal this news before their baby's arrival.
That's what happened to Vanessa*. She and her husband Nate* decided to keep their baby's gender a secret, and all was going well - until Nate's brother guessed they were having a girl.
At first, Nate refused to confirm his brother's suspicions, but later that day he admitted he was right.
When Nate told Vanessa what had happened, she was far from thrilled. "I was annoyed as I didn't want others to be told," she said.
Nate's brother promised to keep the news quiet - which he thankfully did. And Vanessa soon discovered how easy it was to slip up herself.
She was heavily pregnant by that time, and visiting her friend's newborn baby boy when she accidentally referred to her own baby as a "she".
When Vanessa told Nate she'd slipped up, he couldn't help but laugh.
Thea* made a similar blunder when she was pregnant with her first baby.
"[My husband Mike* and I] tried really hard to keep it a secret, not because we're secretive people, but we wanted something special between ourselves," she says.
But one day Thea was talking to a friend about her little girl, and accidentally mentioned something about her own (as-yet unborn) baby girl.
Thea felt so bad about her mistake, she hid it from Mike.
"I actually didn't tell him for a while because I felt like I'd failed him! So it was literally a few months before I decided to let him know the cat was out of the bag."
When she finally confessed, Mike was upset at her inability to keep a secret - but she added, "Because he knew that I'd told [someone] that wouldn't say a word, he wasn't too fussed."
Midwife Amanda Bude from Groovy Babies says it can be very hard for couples to keep their baby's gender a secret.
She says this is especially true when people don't want to refer to their baby as "it".
Couples then oscillate between calling the baby "he" or "she" - and hope not to get 'caught out' by saying one gender too often.
As a midwife, Amanda says it can also be tricky to keep the gender a secret from patients who don't want to know what they're having.
She remembers doing an ultrasound on another midwife once, and accidentally saying, "Oh look, there he is."
She said, "It was the biggest 'oops' ever!"
Interestingly, Amanda says some couples who choose to keep their baby's gender a secret from friends and family will often tell complete strangers what they're having.
"The other thing I see often on Facebook is that mums will tell the sex in online mums groups, but not to close family. But in a group of 5000 people, often the gender is found out through third parties!"
*Names have been changed