It's no secret that plenty of celebrities are obsessed with Harry Potter . Ariana Grande has a dog named Sirius Black, and John Green takes pride in being a Hufflepuff. Now, Blake Lively has proven that she, too, is a truly dedicated Harry Potter fan.The actress posted an image of her Harry Potter manicure on Instagram Tuesday, complete with some carefully chosen emoji. Her nail art features the Sign of the Deathly Hallows, drawn in a light-pink shade of polish.Lively took her fandom a step further, though, with the caption she paired with the image. "I solemnly swear that I am up to no good," she wrote, along with eight uses of the shoe emoji and a scroll emoji to represent the Marauder's Map. Check out her Deathly Hallows-inspired manicure, below.