I went hiking with my sister and her friend

Last summer, I took a week off and flew up to a small town in the northwest to stay with my twin sister, Kelsey. She works for the forest service, so during the week I relaxed at her home while she worked her job. I typically clean, do laundry, get groceries, but mostly sit outside, read and enjoy the mountain air. That weekend we planned to go on a long hike to enjoy some time together.

I was caught a bit off guard by how much she had changed since I last saw her. We've always been close and comfortable around each other growing up. It didn't feel weird for us to share a bed or to see each other in our underwear, but it had really been a while since we'd truly spent time together now that we were adults in our 20s. I never realized how much of a woman she had become and how incredibly well she grew into her body. She wasn't the same innocent teen sister that I had always pictured her to be. It was also a very strange feeling to acknowledge that my sister had become…pretty hot.

She worked out and hiked a lot in the northwest and subsequently became incredibly fit. I couldn't help but admire her body. She had toned legs, a tight round ass, a strong stomach, and yet her breasts were more than a handful. All that paired with her cute face and charismatic personality. She must be unstoppable.

On Thursday, we went out for drinks with her friend, Sally. She was equally as hot, and to my surprise, seemed to have a liking for me. She kept lightly flirting with me all night, and I was reciprocating, but I really didn't know if Kelsey would be okay with it. So when Sally went into the bathroom, I tried to gauge with Kelsey if I had the go-ahead to pursue Sally.

She laughed and said, "Sure! It's actually really cute to see you guys flirt. You know what? Why don't we invite her to go hiking with us tomorrow?"

I guess I was hoping to take her home that night, but that worked too.

And so my sister became my wingman.

The next day we got up early, and Sally met us at Kelsey's place so that we could all head out together. You can tell by the way they dressed that Sally had much more of a clean girl aesthetic compared to Kelsey's nature girl vibe.

The hike itself was going to be 8 hours long, and it also turned out to be a much hotter day than we expected. We were chatting, playing games, exchanging riddles, and telling stories as we went along the trail. Sally kept making flirtatious hints towards me. She kept saying I was going to have to carry her on my shoulders on the way back or that if a bear attacked us, that I would promise to save her.

At around four hours in, Kelsey remembered that there was a small watering hole nearby that would've been a fun detour. It wasn't on the official trails, but Kelsey did this for work and seemed to know what she was doing, so we trusted her, and after another hour of hiking, we came across this beautiful hidden watering hole amongst the mountains.

"This is perfect!" said Sally.

The heat was really getting to us, and the water was incredibly inviting.

"Is anyone going to find us here?" Sally asked Kelsey.

"Probably not," shrugged Kelsey.

The next thing I know, Kelsey is starting to undress.

"What are we supposed to do if our clothes get wet?" asked Sally.

"Well, you either jump in your underwear and wear them wet on the long hike back, or you let them sit in the sun afterwards to dry off and find a spot to tan while you're at it. Orrrrrr….. you can just jump in naked and save yourself all the trouble." She said cheekily. "Since both of you have seen me naked already, I couldn't care less."

As soon as she said that, she lifted her sports bra over her head, exposing her tits to the forest. I hadn't seen them for at least 10 years—they were much fuller than I had remembered. She continued by pulling down her underwear and adding them to the pile of clothes next to her backpack.

I was in shock, to be honest. I never thought of my sister sexually, but suddenly I had become incredibly aroused by her this week and I was… liking it?

Sally was giggling and blushing hard as we watched my sister's perfectly round ass and exposed back walk into the water.

The next thing I know, Sally is kicking off her shoes and socks in a hurry, giggling to herself as she removed her sports bra, revealing the second beautiful pair of tits I had seen that day. This time, they were a bit smaller but equally as perky. She took off her underwear and ran into the water to join Kelsey. They both laughed with each other.

"Come on, Sam!" Yelled Sally. "You have to join the party!"

I was more than happy to do so, but my cock grew hard and fast at the sight of my sister and her friend stripping naked right in front of me.

"Bring us some beers!!" added Kelsey.

"You got it!"

I took my time fishing through my backpack for the small cooler of beers that I had brought. By the time I had undressed, my cock had softened just enough to be in a somewhat presentable state. Both of the girls were whispering into each other's ears and giggled as they watched me carry three beers, completely naked at half staff and walking towards them.

"What's the matter?" I yelled over at them.

"Nothing," Sally smiled.

The water was incredibly refreshing, and the beers were hitting the spot. The conversations got a little bit more giggly, and we started digging into each other's dating lives. Sally complained about the inadequacies of her last sexual partner. Kelsey mentioned that she didn't have time for men, so she had to take care of herself most of the time. I talked about the last few girls I had gone on dates with. I could sense that there was some tension building.

Then Sally decided to go back to our stuff to grab another round of beers. Out of earshot from her, Kelsey gets close to me.

"I got her naked for you, but I can't do everything," she teased.

"Did you get naked for me too?" I teased back.

She blushed and splashed water at me.

"Hey!" I splashed water back. She squealed and we got into a proper water fight.

"Okay, stop! Stop, stop!" she says, catching her breath and clearing her face.

"Not fair! I can't easily reach the bottom like you!"

"How is that my fault?"

She gets closer to me and grabs onto me, propping herself up on my shoulder. Her tits pressed against my arm. Her legs wrapped around mine. Something that felt so normal before was feeling intimate now. I could feel the shape of her hard nipple tease on my upper back. Somehow, in this cold water, my dick starts to get stiff again.

Sally had emerged from the water and she walked towards our stuff. We watched her walk away; her wet body glistening in the sunlight that peeked through the trees.

"Isn't she so hot?" Kelsey whispered in my ear. I nodded while completely entranced.

Then I felt Kelsey's fingers wrap around my cock. In shock, I looked over at her. She's smiling.

Every instinct told me to push her away. My sister shouldn't be doing that. But somehow it was also incredibly exciting.

"Keep looking at her," she says softly yet firmly. She knew the exact tone to strike to get me in line.

I did as told.

Kelsey starts to slowly stroke my cock under the water. A sudden rush of euphoria runs up and down me. My cock gets rock hard in seconds. I am at my sister's mercy. We watched as Sally bent over to look into my backpack, her ass propped up.

"You should know, she really likes to get her ass slapped… nipples sucked on….to get choked as she's about to cum….if you're really lucky, she loves to worship cock too."

I tried not to squirm at the sound of my sister's slow and sultry voice. It was so hot to listen to my horny sister describe her friend's kinks as she controlled me with her hand. It was almost impossible to keep a straight face.

Sally stood back up with three beers in her hands, spun around, and walked towards us. Every inch of her skin exposed. Nothing left to the imagination. She was gorgeous.

"Shhhhh" said Kelsey.

Oh my god, what a smart idea!" Sally yelled. "I was getting tired of being on my tippy toes."

She entered the water and swam towards us. I kept trying to keep it cool.

"Here you go!"

Kelsey removed her hand and grabbed her beer while I grabbed mine. Then Sally propped herself up on my other shoulder. My cock was still hard, it pointed upwards with the flow of the water.

"I'm going to enjoy this while tanning! You guys have fun." She said with a wink at me.

"Aww. Okay!" Replied Sally.

My sister left me so horny. Sally meanwhile seemed to be struggling to float and hold on; she wasn't as enveloped around me as Kelsey was. Yet, she certainly didn't seem to mind being so close while skinny dipping with someone she met less than 24 hours ago. I desperately wanted to fuck her.

"Hold on, I need to open this," she said.

I used my only hand available to reach around her lower back and pull her in. She somehow maneuvered her way in front of me, wrapping her arms around my neck. I heard the beer can hiss and crack open behind me. She smiled at me. And took a sip.

I knew where this was headed and I was getting excited, but I worried not to startle her with my boner, so I tilted my hips away from her. Then, I felt her legs start to wrap around my lower back, and she pulled herself in. I felt my cock graze the length of her underside. I felt the tip pressing along her labia, both her holes, and then rested between her ass cheeks.

She looked at me, eyes wide with red all over her face. Her face switched from surprised to a smirk and she whispered, "Are you…..hard right now?"

"…..yeah" I responded, trying to figure out what else to say. All I could think about was how good it felt to be naked together, her breasts resting on my chest, her ankles resting on my ass, my dick caressed between her cheeks.

Then the current pushed me off balance. I walked with it to keep standing. Again, my cock teased along her underside. Sally caught a small breath of air.

"Sorry!" I said, tilting my hips back again to remove my cock from under her in an attempt to be somehow courteous in this situation, but every time I just kept rubbing my cock against her pussy and ass. And she wasn't letting go. She locked eyes with me, bit her lip, and then tilted her ass up away from my cock. In one slick movement she lowered herself down, the tip of my dick landing at the entrance of her pussy.

We both gasped a little. Another shot of ecstasy ran up and down my body. My cock was desperate to fill Sally, but I was unsure if this would even work underwater. My length twitched as it begged to be let in. She responded with a subsequent breath. She lowered herself more, and my cock pushed its way into her.

"Fuck," I whispered.

Sally smiled. She seemed very delighted with herself.

"Is this okay?" She asked.

"Mhm," I nodded, barely able to keep it under control.

I then looked over Sally to see that Kelsey reached a spot where the sun hit and was laying down a towel.

I started to thrust slowly, back and forth. Her tits pressed against my chest. She lowered her forehead onto mine and started to bounce a little in rhythm with my thrusts. Our pace increased steadily. Every ounce of me needed this. I looked over to see Kelsey was lying down with her knees up, her feet flat on the towel, and her hand in between her legs.

She knew. My sister was watching me fuck her friend, and she was enjoying it too. It only wanted to make me fuck her harder. Sally couldn't contain herself either. The sounds of her moans were sweet.

For the next few minutes, I pounded her while I watched my sister enjoy the show. Then I saw my sister start to shake and raise her feet. Her toes curled, and her head laid back. I could tell she was cumming, and it drove me over the edge.

"I'm gonna fucking cum." I grunted at Sally.

"Yeah?" She moaned. She climbed off, took her free hand below, and jerked my cock as I exploded into the water.

We kissed. I spun her around and made her grab my beer. I held her up with one arm across her torso and played with her pussy with the other as we looked over at my sister, now lying flat. Within a few minutes, Sally came too.

We finished our beers, had lunch, and packed up to go home.