March 2 (UPI) -- Britney Spears is giving a rare glimpse of her sons.
The 39-year-old singer posted a new photo with Sean Preston, 15, and Jayden James, 14, her sons with her ex-husband, Kevin Federline, on Monday.
Spears shared two versions of the photo, which shows her posing with Sean and Jayden outside. In the caption, she reflected on how fast her sons have grown.
"It's so crazy how time flies .... My boys are so big now!!!! I know... I know... it's very hard for any mama especially a mama with boys seeing them grow up so fast!!!! Talk about enough to make you go to your knees... GEEZ!!!!" Spears wrote.
Spears said she usually doesn't post photos of her sons in order to respect their privacy.
"I'm extremely lucky because my two babies are such gentleman and so kind that I must have done something right!!!!" the star said.
"I haven't posted pictures of them for some time cause they're at the age where they want to express their own identities and I totally get it.... But I went out of my way to make this cool edit and guess what.... They're finally letting me post it!!!" she added.
Spears referenced her sons on Instagram in September in anticipation of their birthdays.
"My two lil men's birthdays are this week!!!!!! You guys are getting older and so big and are waaay cooler than me!!!!! I love you both to the moon and back ..... and I hope all your bday wishes come true and more!!!!!" she wrote.
Spears previously shared a photo with her sons in 2018, saying, "The boys are bigger than me now!!!!"
Sources told People in March 2020 that Sean and Jayden primarily live with Federline but still spend time with Spears. Federline has four other children, including two daughters with his wife, Victoria Prince.