My sister forced me to tie her up and perform sexual acts on her

I'm not sure what to make of this situation. My sister came barging into my room, a wild look in her eyes, demanding that I tie her up and perform sexual acts on her. I was taken aback, unsure of how to react. But as the situation escalated, I found myself succumbing to her desires. My friend, a well-endowed man with a monstrous cock, joined in, and we engaged in a steamy threesome with my sister. It was a sight to behold, her petite frame writhing in pleasure as we ravished her. Her smooth, hairless skin glimmered under the soft light, her luscious ass and shaved pussy yearning for more. The sensation of her tight, welcoming pussy wrapped around my throbbing cock was nothing short of mind-blowing. The sight of my friend's massive cock plunging into her, a testament to his impressive size, was a sight I won't soon forget. As the night wore on, we continued our debauchery, leaving us all spent and satisfied.