The bathroom, their secret haven, is where these teen siblings explore their taboo desires. The eldest brother, his cock aching with need, guides his younger sisters' hands to it. They gasp, their eyes wide with curiosity and fear, but their fingers wrap around his shaft, tentatively at first, then with growing confidence. He teaches them how to stroke him, how to make him groan with pleasure. They learn quickly, their inexperienced hands clumsy yet earnest. The room echoes with their hushed whispers and soft giggles, their shared secret creating an intimacy that's both exciting and dangerous.