Bellatrix/Sirius, eyeliner
There was almost nothing between them now Sirius had grown his hair. Their smiles worried people the exact same amount, and after a long night of dancing, when eyeliner smeared both of their faces and hair plastered itself to their foreheads they could have been twins. And people stared at them twined together, wanting their beauty, wanting them wanting each other, wanting not wanting, and the wrongness was a part of it, and Bellatrix’s smile that made Sirius want her and take her and call out her name and tell her she’d kill him as she told him she knew.