She couldn't see anything. She couldn't move. Her hands were carefully locked in place by her captor. She could feel breathing on her neck and it sent shivers up her spine. Sweat beaded on her forehead. She knew that her fear could be smelled, and she tried as hard as she could to push it away. She couldn't show fear. She hated herself for it, but she was excited. The silk ties that bound her hands to the posts wouldn't give, leaving her with absolutely no control. She always had control. She was used to it. Control fit her like a glove, bending at her whim. But not today. Hands slid up her naked torso, almost seductively. She let her mind slip away. This is a game, she told herself over and over. This is just a game. The weight on her waist shifted, and for a moment she felt nothing. Suddenly, hands gripped her forearms. Nails dug into her soft flesh, painfully deep. She smelled her future, hovering precariously above her face. A familiar voice sounded. "Eat my cunt like a good girl, Cissy." Narcissa couldn't help the smile that escaped her lips. The blindfold prevented her seeing anything, but she knew what was coming.
"Goddammit, Cissy!" Bellatrix shouted. "This is why I hate roleplaying with you! You never stay in character!" A swift palm met her cheek, sending a ripple of pleasure straight to her core. Sometimes it was worth breaking the rules, if only to feel her sister's sweet wrath.
A/N: What did you think? I am considering developing this theme a little more with a longer story, so let me know if I should!