You don’t need a pair of jeans to prove that there’s something special between Blake Lively and Robyn Lively.

If the Gossip GirlOn Aug. 25, the alum reached 35 years old. Robyn, her half-sister celebrated with a photo collage of them throughout the years. The tribute was posted on Instagram by the Teen WitchStar wrote “Awww! You’re my best buddy.”

Robyn said, “Now everybody knows that you are barely younger than I.” Happy Birthday, sweet sissy! You’re a very special person to me.

Nearly two weeks have passed since Blake and Robyn went to Disneyland for a birthday party. The following photos were shared by the Sisterhood of the Traveling Pants actress, the two were seen posing for a selfie by Sleeping Beauty Castle at the Southern California theme park, before hopping over across the plaza to Disney California Adventure Park for a nighttime hang at Pixar Pier.

Blake shared the following Instagram message: “Find me an easier place on Earth to celebrate my birthday early,” Blake said Aug. 14. “I’ll wait…”