In the height of summer, my air conditioner broke, so I was cooling off in a vinyl pool. Then my sister came back to her hometown with my niece. When she saw the vinyl pool, my niece got super excited! Even though I was in it, she quickly changed into a swimskin and started playing innocently. Watching my niece's erect nipples and peeking butt made me involuntarily get hard. Of course, she noticed, and I thought it was dangerous, but my niece, who had grown not just physically but mentally as well, was fascinated by my dick and reached out her hand…
