The rule was simple: you don't fall for your older brother’s best friend. I kept that rule perfectly ever since the rainy Tuesday Ethan first dragged Caleb into our cramped apartment. For years, I mastered the art of being invisible, accepting every playful hair-ruffle and "hey kiddo" Caleb threw my way. It was safer to let him see me as a younger sister than to risk him knowing the truth. But a single second destroyed years of careful hiding. My foot slipped on the fire escape stairs, and Caleb caught me, pinning my back against his chest. When I looked up, his grip didn't loosen, his eyes dropped to my lips, and the safe, familiar "big brother" gaze vanished entirely. After that incident I tried my best to stay away from Caleb until… At Ethan's chaotic promotion party, a random guy tried to flirt with me at the bar. Before I could answer, a heavy arm wrapped securely around my waist. I expected to see Ethan, but I looked up into Caleb’s dark, fiercely territorial eyes. "She's not interested," Caleb muttered, his voice dropping kinda scary*