Britney Spears celebrated her sons Sean and Jayden's birthday parties on Sept. 13. Credit: Courtesy Britney Spears; Kevin Mazur/Getty Image (inset)

All grown up! Britney Spears' two baby boys are babies no more. Sean and Jayden both celebrated their birthdays on Saturday, Sept. 13. Little Sean Preston, whose official birthday is Sept. 14, turned 9, and Jayden, whose official birthday is Sept. 12, turned 8. 

"Happy Birthday to my two little baby boys. They are growing up too fast!!!" Spears captioned a picture of her children at their skateboard-themed party. 

The sons, whom Spears shares with ex-hubby Kevin Federline, posed with skateboard helmets and safety pads in front of a table of treats, including helmet and skateboard-themed cakepops. 

In July the Las Vegas performer took her boys to Disneyland to share some of the magic from her Mouseketeer days. 

"Took these two little Mouseketeers to @Disneyland today," she wrote. "Like mama like sons ;)"

Moments with her kids are helping to boost the newly-single singer's spirits these days. Spears has publicly announced that her boyfriend David Lucado cheated on her after 17 months of dating. 

"The best thing about your boyfriend cheating on you is that you get to go on another first date!" she said during the Las Vegas show on Sunday, Aug. 31. "O-M-G a first date!"