Sandra my girlfriend sister had come to visit us after she had graduated from university. Sandra decided to take the entire summer off to recoup from all the hard work that she had done during her studies, she planned to stay with us for three or four weeks. Kelly and I lived in a mountainous area which was great because we both enjoyed hiking, both Kelly and I are very physically fit so whenever we go for a hike, we like to go for the difficult hikes so that we get a good workout. Her sister Sandra idea of a physical workout is to stretch out with her legs extended on the La-Z-Boy and every once in a while, push down with her legs so that she could stand up. One Saturday morning Kelly and I decided to the mountains and hike to one of the many Hot Spring locations. She told Sandra that we would be gone for three or four hours and when they came back, they could go shopping. I was surprised when Sandra asked if she could go with us. Kelly told her that the hike was no picnic and would give her a real workout, Sandra shrugged and said it beats staying around the house all morning.
We packed some water a medical kit and a few snacks, our swimsuits and towels into a couple of backpacks and were ready to go in about 10 minutes. It only took me about 30 minutes to arrive at the trailhead. It was about 65° when we got to the trailhead, both Kelly and I were wearing light fitting shirts, shorts, and good hiking boots. Sandra was wearing a slim top, shorts and a pair of designers running shoes which looked nice but were not much good for hiking. Sandra is about five foot eight and weighed about 110 pounds she had tiny breasts and a very slim waistline. In many ways she could pass for a teenage boy, because she wears her hair tightly cropped to her head. Her breasts were almost invisible under her shirt. After parking we walked to the head of the path it sloped down onto the valley floor at about a twenty-five ° angle gradually leveling out before, going down again. Normally it would take Kelly and I about 45 minutes to reach the bottom of the trail, but with Sandra long we had to stop several times for her to take a break. I whispered to Kelly that Sandra was really going to hate the climb back out of the valley.
Once we got to the bottom, we went into the wooden shack so that we could change into our swimsuits. Kelly and I liked to go into the hot pool first get nice and relaxed and then go to the cool and then eventually cold pools, we had worked our way through the pool several times, before I heard Sandra yelled that she had stepped on something sharp and cut her foot. I helped her to the edge of the pond; Kelly got some water so that we could wash off her foot to see how bad it was. Sandra had about an inch long gash across her in-step. I got the first-aid kit some antiseptics wipes, cleaned up the cut and bandaged it. When Sandra stood up, she said her foot hurt and that she could not stand on it. I started to wonder how we were going to get her back up the steep trail since she could not walk. Kelly and I changed back into our hiking gear, and I said that I would have to carry Sandra back up the trail. I had often carried very heavy packs during my deployments to Afghanistan, so I was fairly confident that I would be able to piggyback Sandra up the trail. We reorganize the backpack so that Kelly took anything heavy and left Sandra with a backpack that contained four bottles of water. My idea was that she could wear the backpack while I carried her on my back. I told Sandra to put her arms around my neck and to wrap her legs around my hips and started up the trail, but her legs kept sliding down. So, I put my hands behind my back forming a bit of a seat after a couple of tries we managed to get a position that would work.
I had removed my shirt and since Sandra was still wearing her swimsuit the coolness felt good against my back. There were benches located about every hundred feet so we could stop and rest, after walking for about 10 minutes, I realized that my thumbs were resting right against her pussy mound every time I took a step, I could feel her mound push into my thumbs. After I had stopped for a short rest then started walking again, I position my thumbs so I could feel the outline of her pussy, Sandra pull away when she felt the pressure against her pussy, after a couple minutes I could feel her relax her hips, I gently rubbed the material over her pussy with my thumb. After the third rest stop, I suggested that Kelly should go ahead of us so that she could move our SUV closer to the trailhead. She did not want to but after a bit of discussion she agreed to the idea. When Sandra climbed back onto my back, I position my palm so each one held one of her ass cheeks and my thumbs were free to continue exploring her pussy. As we walked along, I was able to slide one thumb under the edge of her swimsuit and feel the wetness of her pussy. I heard Sandra mumble something, so I stopped and asked if she was okay, and if she want me to stop. Her response was to lift her waist away from my hip enough that my thumb slid into her wet hole. When I started walking again, she started to grind her hips fucking my thumb. At the next stop I asked her to sit sideways on the bench so that I could check her bandaged foot. As I bent down to check the bandage, Sandra spread her legs which gave me a clear view of her hairless cunt. As I stood up I reaching to take a bottle of water out of her backpack, Sandra moved her hand under my shorts and started to stroke the shaft of my cock. I thought about finding a secluded area alongside the trail and fucking her right there on the side of the mountain. Before I could do anything, Sandra met my eyes before saying oh there are some people walking up the trail. My cock instantly deflated, and I turned to meet the other people.
With the help of one of the other men, we locked arms and made a seat so it would be easier to carry Sandra up the last part of the trail. We met Kelly at the trailhead easily transferring Sandra to the rear seat of the SUV. I thanked the other man as Kelly helped Sandra change out of her swimsuit. Then we headed back towards the medical clinic in town to have them look at Sandra’s foot. An hour and one-half later we were back in our apartment, the medical staff had stitched her foot and given Sandra a tetanus shot. We had had planned to go for supper but Sandra said she did not feel like walking on her injured foot so Kelly decided to drive into town and pick up a couple of pizza’s. I said that I would change out of my grubby clothing and have a quick shower. I was in our main bathroom when I heard Sandra called out to me. She was naked standing near the bed, she said that she wanted to thank me for carrying her up the trail. She then rested palms against the frame of the window with her back to me, she said we had about 10 minutes. I walked in behind her sliding my hands around and feeling her breasts, her tiny nipples quickly became erect. My cock quickly became hard, and I shoved it against her pussy lips, it easily slid in, and I started moving my hips faster and faster thrusting deep inside her. Within five minutes I could feel that I was going to ejaculate, I said I am going to shoot my load before ejaculating three strong streams into her wet pussy. My cock relaxed and slipped out of her wet hole. Sandra turned around and kissed me on the mouth and said that was just a down payment the next time when we had more time and she would show me how thankful she was. With that she turned and walked out of the bedroom. I quickly went into the shower stroking my cock to make sure that no cum would leak out.
I was dressed and had laid out some plates and utensils by the time Kelly walked through the door. We all enjoyed the pizza and pleasant conversation before settling down and watching a couple of movies. That night as I lay in bed with Kelly, she performed oral sex on me, which is something that she rarely did, she said that she wanted to reward me for helping her sister.