In the dimly lit attic, siblings find themselves alone once more, drawn to each other like magnets. They've danced this dance before, their bodies remembering the rhythm even as their minds struggle with the taboo. She's in her usual lace, he in loose cotton, their breathing syncing as they near. This time, she takes the lead, her fingers tracing the familiar path up his thigh, while he watches, his cock thickening in response.