"Of course I knew you wouldn't tell them. I only acknowledged that aloud to make you feel special. What are sisters for, if not to keep secrets for each other?" Bellatrix asked, relishing the hurt look on Narcissa's face and reaching for her hand. "Don't take everything so seriously. And I'm glad you're with Lucius because you want to be. But if he starts bringing you down, you just tell me. I'll hex the life out of him."
She gave Narcissa a devious wink. She was only kidding, of course, but she was sure her sister would take that the wrong way as well.