In the confines of their shared bathroom, a Spanish brother and sister, bored and curious, turn to self-pleasure. The brother, with his enormous cock, strokes it to full hardness, while his sister masturbates her tight pussy, fantasy painting her face. 'Es grande?' she asks, her eyes locked onto his massive member. Their secret game escalates when she suggests they compare sizes, their bodies pressing together, sweat mixing as they rub each other towards explosive, simultaneous orgasms.