My sister, who's married and raising a daughter alone, asked me to watch her niece for a few days while she's on a business trip. It had been years since I last saw her, but my niece had grown so much taller and her breasts were now fully developed, her school uniform blouse straining at the seams. I tried to calm myself down, reminding myself she's my niece! But faced with her innocent, bouncing breasts, my primal instincts took over, and I couldn't help but experience a close-relative erection. When she noticed my aroused cock, she gleefully squeezed it with her firm, elastic breasts! I came instantly from the intense stimulation, and she kept pulling me out and in until my balls were completely empty.
