Cole Sprouse is ready to be an uncle. The Riverdale alum, 33, took to his Instagram Story on Thursday, May 14, to react to a photo of his pregnant sister-in-law, Barbara Palvin, and his twin brother, Dylan Sprouse, at the 79th annual Cannes Film Festival in France. The image showed Palvin, 32, wearing a baby blue gown as she cradled her baby bump on the red carpet. With her other hand, she reached out to Dylan, who sported a black suit as he admired his wife. "❤️❤️❤️," Cole wrote over the photo. Palvin and Dylan announced earlier on Thursday that they're expecting their first baby.