”Hi,” a voice said.It was Rita, Rina’s younger sister who was just finishing high school and just had her 18th birthday.”Hi Rita; I didn’t e...pect you to be home on a Saturday night; no date?””No, so Rina said I could hang out with you two for a while and chaperone since my parents are away; is that OK?”Her teasing tone of voice suggested that clearly she was aware of Rina’s interest in me!”Sure,” I said. Rita is shorter than her sister with green-grey eyes, a pretty upturned nose and medium. "Don't worry about it" she said, "just relax and enjoy this..." I started to thrust in and out of her but she whispered "Don't move like that. Someone will see us. Keep still and let me do everything." She closed her eyes and I was wondering what was coming next. Then I felt it. Her pussy momentarily tightened and relaxed. And then again. She wiggled her hips. She opened her eyes "Like that?" she breathed. I nodded in the affirmative. She closed her eyes again and once more I felt her internal. She hesitated: "I can get my undergarments wet. hm...". She then quickly turned her back at me, removed her remaining wear, and ran into the water. It was just deep enough for her to hide, at least some, and she called for me to join. I finally took all my clothes off, before quickly joining her in the water.At first, she kept some distance, chatting about the warm water, amazing weather, and noticing the strong effort I put in, focusing on Olka's face, rather than what I really wanted to look. She yanked on the leash to pull me up and ordered me to get undressed. I guess I was not fast enough because I felt another harder sting across my ass. I was led into the bedroom where I was asked for a safety word but warned that if I used it had better be for real. It was not to be used just because I was uncomfortable or uneasy only if I was really being hurt. I was then blindfolded so I couldn't see anything. I could tell from the sounds that everyone else was getting undressed. I felt a.