Zac Efron proved this weekend that his charm definitely has no limit. On Monday, the actor shared a sweet message for his girlfriend, model Sami Miró, on Instagram in honor of their anniversary. In the photo, the couple, who began dating last September [2], is seen standing on what appears to be a hotel room balcony as Sami snaps their reflection in a glass door. Zac plants a sweet kiss on Sami's head as she leans back into him. "Happy anniversary baby :) I love you @samimiro September 5th," Zac captioned the photo. Sami also took to Instagram to share a cute photo of her and Zac, writing, "Time flies when you're having fun. Happy anniversary baby I love you too @zacefron September 5." The pair's special day comes just a few weeks after they attended their first red carpet event together [3]. They've also shared many adorable moments together on social media [4].