The girls partied with family members including mom Kris, dad Bruce and brother Robert Kardashian at the party.
Kendall also had a Colossal CRUMB (giant cupcake) from CRUMBS Bake Shop. She actually got in a cupcake fight with Kylie after cutting into it!
Kendall shared with ET, “This was the perfect way to celebrate my birthday and Sony PlayStation’s birthday, because it was each of our 15th birthdays. It was just like a coincidence that it was both of our birthdays. â€¦ The big one-five!”