Carrie Underwood says she got a new tattoo because her 74-year-old mother asked to get matching ink with her family in Las Vegas

• Carrie Underwood revealed that she got matching heart tattoos with her family over the weekend.
• The "American Idol" winner said the ink was her 74-year-old mother's idea.
• Underwood has other tattoos, including one of a flower and another of a four-leaf clover.

No matter how well you know your parents, they can surprise you.

Carrie Underwood talked about that feeling in an Instagram post on Sunday, in which she revealed that she got matching heart tattoos with her family after wrapping a brief concert residency in Las Vegas, Nevada.

"When your 74-year-old mother asks you and your sisters to get matching tattoos with her in Vegas, the only questions are, 'what?' and 'where?' I never would've thought I'd see the day that Mama Carole would be gettin' some ink! ????❤️ #WhatHappensInVegas," she wrote.

While Underwood's mom and sisters had their heart tattoos placed on their wrists, the "Take Me Out" singer had hers done on her right foot. 

She shared photos of herself getting the tattoo, and a shot of the final result.

The "American Idol" winner also thanked tattoo artist Darek Riley for "being so sweet to the Underwood girls" and giving them their matching ink.

"Experiences like this make Las Vegas one of the coolest places to live!" Riley wrote on Instagram. "A huge thank you to the Underwood gals for coming by and spending the afternoon in my studio. I am so grateful ????"

Underwood's other tattoos include a four-leaf clover on her waist, and a flower on her arm that she got on a trip to Florida with friends.