Mason Disick became a big brother last weekend when his mom, Kourtney Kardashian, gave birth to Penelope Scotland Disick -- but even with a new baby in the family, Mason still has everyone's attention.
On Saturday, the reality-TV family's most adorable member frolicked on the beach with his 16-year-old aunt, Kendall Jenner. The teenage model sported a turquoise bikini as she and Mason played along the Malibu shoreline, throwing around a football.
The pair looked like they had a blast and were also joined by Kendall's 14-year-old sister, Kylie, and friends.
After getting their fill of the waves, the group packed up and later shared a post-beach treat with their Twitter followers. The sisters posted a short video of Kendall driving home from the beach, as they sang along to Kanye West's hit song "Mercy."
PHOTO: More stars on the beach: