In the steamy bathroom, siblings, both stressed from the day, enter the shower at the same time. She's the first to notice his growing erection as he lathers up, trying to hide it. Her eyes widen, and she licks her lips, unable to resist the temptation of his hard cock. He turns to face her, his body tense with desire. She reaches out, wrapping her soapy hand around his shaft, stroking him slowly. He groans, leaning back against the tiles as she increases her pace, her other hand cupping his heavy balls.