When I thought my sister, who I live with, had just come home from a drunken romp, she fell asleep in the bathroom! What's more, she was completely soaked with her clothes on, with the shower on full blast! Seeing her like that, rather than worrying that she'd catch a cold, I stared at her see-through bra and panties and got a forbidden erection! Then, my sister woke up at the perfect time, still drunk, and mistaking my brother for her boyfriend, she reached for the erect penis in front of her and suddenly put it in her mouth! I was surprised by my sister's unexpected behavior, but my brother lost his senses at her lewd behavior...