This past summer my family went on vacation, and at the hotel we stayed at, my parents stayed in one room and my one year older sister and I stayed by ourselves in a cheaper room across the parking lot. The biggest part of us staying alone is, my sister and I could not be any more different. We kind of get along, but we have almost nothing in common. She takes after my mom, is about 5'6' with long hair and a very nice body, while I am like my dad. I am 5'3', frizzy hair, small breasts and glasses. Not only that, I have never had a boyfriend while she started having sex before she was in high school. Either with someone or masturbating, I can hear her having an orgasm almost nightly. I masturbate too, but nothing like her.
Anyway, the one night we were there, she went first to take a shower and when she was done she dried off and walked back to her bed naked and sat down. I went to take my shower and when I was finished I put on my t-shirt and pajama pants, and when I walked out she was still naked with her ankles crossed looking at a magazine, not trying to hide herself one bit. I laid there for a while watching TV, but when I started getting tired I asked her if I could turn off the light, and she said that was fine and we went to bed.
After a couple hours I was woken up by something moving, and when my eyes adjusted she was down by her suitcase digging through it. When she found what she was looking for she jumped back in bed, and then I heard buzzing. She actually brought her vibrator on vacation with her. Not only that, she wasn't trying to be quiet about it either, and she started moaning and panting as she got closer to her orgasm. Seconds later she took a deep breath and said out loud 'oh...oh...oh yeah that's goooood...', squirmed around and let out a long 'mmmmmmm' as she relaxed. By this time I was extremely horny myself and decided then and there she wasn't going to have all the fun, so I stood up and stripped off my clothes, sat back down on the bed facing her and started rubbing my wet pussy with my legs wide open. I could see that she was watching me, but that's exactly what I wanted. When I was really feeling it building up, I leaned back and put my feet on her bed, rubbing myself hard and fast. Just feeling her eyes on me made me cum hard, and I moaned loudly just to let her know I came. I laid there for a few seconds catching my breath, then she reached over and started squeezing my toes, asking how it was. I told her it was fantastic and asked about hers, she said it was wonderful. We talked for a little bit about it then went to bed, me sleeping naked for the first time and quietly masturbating again before dawn.
After that we were a little more open around each other, but not much changed. However, now after I hear her having an orgasm, I let her know when I had one of my own.