There was absolutely nothing to do in this small town our parents moved to in the middle of nowhere. Even the internet and phone service was unreliable, making sitting around the house so boring. About the only thing there was for my kid sister, who was three years younger, and I to do to entertain ourselves was the beach on the lake on the far side of our parents property. It was close enough to walk to but separated enough from everything by the copse of trees you had to go through that it gave a real sense of privacy.
One day, while I was swimming, enjoying the cool crisp water, and she was sitting on the sand watching me, an idea came to mind. She had an almost flat chest. Had she ever felt another girl's breasts before? I thought that I would play a naughty prank on her. As a horny teenage girl, especially one living here in this town where prospects for other girls were very limited, the temptation became irresistible to have a little fun and gauge her reaction.
As I walked out of the water, I reached behind my back and untied the string holding up my bikini top. It fell free and a smirk spread ear-to-ear on my face. I was developed, and there was more than enough to my perky breasts that they could jiggle ever so slightly as I strode topless up the beach with a deliberate sway of my hips.
If she had looked away or complained, or even got up and ran, that would have been the end of it, but she didn't, just sitting there stunned as I closed the distance. Her eyes were mesmerized. "Hey," I said nonchalantly, "Do you know how to massage your breasts to check for breast cancer? It's a pretty important skill. Did you want to practice on me?" Eagerly, she walked up to me and caressed one of my breasts. I could feel my arousal forming, a deep warmth inside me.