This isn't the first time Bec has been open about her boobs - the mum-of-four shared a jaw-dropping picture of herself when she was breastfeeding that appeared in her book The Baby Bible.
"I looked ridiculous ... like Dolly Parton on steroids," the mum-of-four told news.com.au in 2018 adding that breastfeeding was particularly painful.
“I was a blubbering mess for two days with these bloody boobs. To touch them was like touching a wall. They were rock hard. It was awful. They were boiling hot. Burning hot.
“I was skinny arms and legs and bazookas out to here.”
Bec's twins seem to be the most mischievous of her four children as this isn't the first time Bec has shared a story about their cheeky behaviour.
In April, the activewear mogul locked herself in her bedroom to do some work without the twins interfering and recalled the story on air.
"I thought, 'God, they're going to come in and bang the door down.' So I snuck into the ensuite and sat on the toilet with my laptop. God, I was efficient," Bec said, but unbeknownst to her, the kids managed to break in.
Playing a short clip she recorded after they burst through the door, the perplexed activewear mogul could be heard asking one of her toddlers how they entered the room, however "it's still a mystery".
Bec and Chris are proud parents to eight-year-old son Oscar, five-year-old daughter Billie, and twin boys Tom and Darcy who are nearly four.
The couple have been married since 2010 but Bec has admitted that like any husband and wife, they have the odd argument. However, Bec revealed that listening to 90s ballad Love... Thy Will Be Done by Martika helps her to fall back in love with Chris after a fight.
"I have a romance Spotify list, and that's on there. If I'm ever feeling not in love with my husband, I put that song on and then bang, we're back on!" she explained.