So, this is my first attempt at an erotic story, so any constructive criticism is appreciated. This is 100% fantasy, or wishful thinking on my part, take your pick, hahaha. Everyone in the story is 18 . Hope you enjoy!

"We are going to be late", I tell my wife and daughter. My sister and brother-in-law were having a family get together and if it was like any other time, it would be a good way to spend the afternoon with family and friends. They have a wonderful back yard and full-size swimming pool, so on the hot days most of the time is spent drinking and swimming in the pool. They have a large house as well, so it isn't a problem if we all have a bit too much to drink and need to spend the night. "Almost ready" I hear both my wife and daughter call out. "I'm heading out to the car to get the A/C running, hurry it up!" I yelled back.

I open the door to the car, and I am almost pushed back by the heatwave that comes rushing out. I reach in and slip the key in the ignition and turn. I hear the fan kick in on high and I roll the window down slightly to let some of the heat escape. I shut the door and decide to walk over into a shaded area to wait for the rest of the family. It was worth the wait as I see my 18-year-old daughter, Allison comes out of the house first. She has a loose t-shirt covering her pert young breasts, barely long enough to cover her cute ass which is trying it's best to suck her bikini bottom between her cheeks. At 5'2" she really starting to fill out in the past year. Her long black hair pulled into a ponytail, but still long enough to reach just below her shoulder blades. She is carrying her beach bag with all of her "necessities" for a trip to the pool. A short time later my wife Becky comes out the door, a slightly taller version of my daughter, but she is a little bit more conservative in what she is wearing. Still, she can get me going with the outfit she had on. She had a ballcap with her hair pulled through the opening in the back, she had on a t-shirt, which her tits made stand away from her smooth belly, and the shorts.... oh wow, I almost wish the car hadn't started so we could go back inside, and I could yank them down and take her from behind. "Are you coming babe?" she called to me, snapping me out of my memorized state.

On the way over to the car, I clicked the key fob and heard the "click" of the locks opening. I climbed in just in time to hear both my wife and daughter let out a little yelp as their bare legs touched on the hot leather seats. "You should have seen that coming you two", I chuckle as I turn to look at my wife, then my daughter in the back seat. Did I just catch a glimpse of a camel toe poking from her bikini bottoms? I shake my head and turn to head out the driveway.

The trip didn't take long, about 20 minutes, and when we got there and opened the doors, you could already smell the smoker going. I climb out of the car and wave to my sister as she comes out of the house to greet us. She hugs my wife and daughter, then comes to give me a hug as well. "Here let me help you guys with your stuff," she says. I get the cooler out and start to haul it to the back yard, while the three girls head inside the house with all the other goodies.

I walked up to the gate leading into the back yard, and as I shifted the cooler to work the latch on the gate, I felt a twinge in my neck. I almost dropped the cooler as I winced in pain but managed to keep hold of it and get the gate open. I went over next to the smoker where my brother-in-law was and set the cooler down, then reaching immediately for my neck to rub out the muscle spasm. "What happened to you?", Brian, my brother-in-law asked. "Nothing major, I just turned wrong coming through the gate." I replied. "I've got this, go inside and get your suit on, and before you get in the pool, hit the jacuzzi and let the jets hit you for a few." He offered. "Thanks", I turned to head into the house and find my suit that was packed in the rest of the stuff we brought.

I get to the door just in time to open it for my niece, who was coming out in her bikini. She was the same age as my daughter, but she definitely got my sisters breasts and her cute, firm little ass. There was so much side boob I couldn't help by stare, and she caught me looking and gave a laugh as she playfully punched me in the arm. I caught the playfulness in her eye as she whipped her long blond hair around and bounced off to join my daughter in the pool. I went inside and found my wife and sister in the kitchen chatting away. Both had their backs to me, and I took a moment to admire both. I always thought my sister could be considered "hot" by any standard. Looking at her ass in her bathing suit reminded me of that fact, she was a few years younger than I was, the same age as my wife. Her blond hair was not as long as my wife's but was tied into a ponytail as well. I walk up behind my wife and pinch her ass through her shorts and gave her a kiss on the neck. "Where is my swimsuit baby?" I ask. She tells me the bag with our stuff is in the spare bedroom upstairs, so I head off to change. I close the door behind me and start to get changed. I can hear Allison and Madison outside splashing in the pool to see who could dunk who first. I walked over to the window to look out and watch them for a minute. They were so engrossed in their task I wasn't worried about them seeing me, so I started to get changed while continuing to watch. I pulled my shirt over my head and tossed it on the side of the bed, then slid my shorts and underwear down and kicked them onto the bed. The motion in the window must have caught my niece's eye and she looked up at the window just in time to see me turn around and flash her. I quickly backed away from the window and cursed myself for my stupidity. I finished grabbed my swim trunks and stepped into them quickly and made my way downstairs.

As I walked through the kitchen and wave to the girls. "Are you ladies coming outside soon?" I asked. "We will later, after we get everything prepped for this afternoon", my sister Cheryl replied. I waved and walked out the back door onto the deck.

I walked down towards the pool and found a chair with a beach towel folded on it. Two of the other chairs had the towels already stretched out over them, presumably Madison and Allison's. I picked a chair away from the girls, in case the closer one was Madison's. I was still a little embarrassed at having been spotted earlier. I laid out the blanket on my chair and went over to a table that had the sunscreen on it and a cooler underneath it. I opened the cooler and grabbed a beer. Before I opened it, I placed the cold can against the muscle in my neck. I closed my eyes and enjoyed the brief reprieve from the pain. I opened my eyes just in time to see Madison walking over to me. Fresh out of the pool, her hair was wet, and she was working on drying off the excess water from her body as she walked over to me. "Hey Uncle Marc", she gave me a devilish smile as she got closer. "Do you want me to help put some lotion on you?" I smiled back at her, trying to not let my eyes scan up and down her body. She watched me as I couldn't help but sneak a peek. Her nipples were poking against her top, and some water was still dripping down between her legs. Her entire body glistening in the sunshine, "what am I doing, she is your niece," I tell myself. I hand her the suntan spray bottle and quickly turn around to try and avoid her noticing a slight tent building in my swim trunks. I sit down on the edge of the pool chair and feel, or sense her swing her leg over the chair as she sits down behind me. "You don't want the spray Uncle Marc, here let me use this instead". I hear a squirting noise followed by her rubbing her hands together, before I feel her touch against my back.

I take a sip of my beer and close my eyes as she starts to apply the lotion to my shoulders. I let a soft groan escape as she moves over the sore muscle. Softly, she leans against me and whispers in my ear "Thank you for the view earlier Uncle Marc, I don't want to be to forward, but I'm going to have to find a way to inspect you a little closer" She giggled as she pulled back and finished rubbing the lotion onto my back and shoulders. Did I just hear what I thought I did? My cock started to stir in my swim trunks at the feel of her warm breath against my ear as she whispered to me.

I coughed, clearing my throat and quietly whispered "on one condition". She heard me and I felt her hands work the lotion in with more of a massage than application. "And what would that be Uncle Marc?"

"I get to inspect you as well".

"You have a deal!"

She continued to rub the knot in my shoulder until I felt it relax a bit. "Thank you, Madi, I needed that."

"I'm going to head to the pool for a bit, I'm getting a bit hot just sitting here" Madison said. She stood up and came around the chair, walking towards the pool, keenly aware that my eyes were glued to her round ass that was trying so hard not to stay in her bikini bottoms.

I saw Allison watching her as well as she made it to the edge of the pool. Then she jumped in while yelling "Cannon Ball!" The splash caught Allison off guard, and I saw her shake her head and try to wipe the water from her eyes. Just in time for her to see Madison coming up to her and playfully try to dunk her. I stood up and started to make my way over to the diving board. As I reached the end, I saw both girls stop to watch. Madison was behind Allison, and I saw her whisper something in Allsion's ear that made Allison's eyes grow wide. I made my way to the end of the board and did a simple dive into the water and swam under the water until I reached the girls, and I came up brushing the water back from my face.

I looked at both girls, and I saw Allison flush and turn to avert her face. I wondered what Madison had whispered to her, but before I could think to ask, Allison made her way to the ladder and started to climb out. "I'll be back in a few" she said. I watched as she climbed out of the pool, the water dripping off over her tight young body. Just then I felt someone against my back, Madison's breasts pushed against my back as she wrapped her arms around my body. I started to grab her hands and push them away, but she ran them down my stomach and over the front of my trunks, instantly making my cock spring to life. "What if someone sees us?!", I growled softly. I heard her giggle behind me as she said, "I think everyone is going to be distracted enough that we won't have to worry." I looked over at the smoker and notice Brian was no longer there. I wasn't sure where Allison had got too.

"What are you two up to?", I ask. "Oh, nothing just a little bet we made with each other", was her reply. I felt her hand grab onto my hard shaft and give it a gentle squeeze through my trunks. Her hand comes back up to my stomach, and I feel her working at the strings of my trunks. Before I knew it her hand had pushed my trunks down and she had reached in and grabbed a hold of my now pulsing cock. I let out a grunt as I felt her soft fingers wrap around it and start to pump it slowly. Madison's hand released my throbbing member, and she moved around in front of me. She reached up to my chest and started to push me back until I was leaning against the edge of the pool. I turned to look behind me and saw that Allison and Brian were nowhere to be seen. I wondered where they had disappeared to.

I quickly dismissed the thought from my mind as I felt Madison tugging down on my swimsuit. I felt my tool spring free from the top of my trunks, and she quickly wrapped her hand around my shaft again and began pumping. Her wet cleavage showing just in front of me, and I reached out to cup one of her breasts. Her nipple was hard against the fabric, and as I teased it through the material, I felt her grip on my cock get tighter as she let out a little whimper. I slipped my hand underneath her top and felt her soft flesh against my hand. I squeezed and milked her pert young tit while she continued to pump my shaft. Suddenly she dropped down in front of me and went under water. It took all control I had when I felt her warm mouth close around the tip of my cock and start to take me in. I looked down to see her start to bob her head on my dick, and then she took me deep in her mouth, I could feel the tip of my cock pressing against the back of her throat. She released me and surfaced with a sultry smile. "How was that Uncle Marc?" She asked. "Hmm, I think it is too early to tell, maybe try it again..." I pushed on the top of her head and she took the direction and a deep breath before she submerged again. I felt her mouth again take me in and she started to suck while playing with my balls. Her head was bobbing back and forth and then again she took me all the way to the back of her throat, holding me there until I thought she was going to drown. She came back up and was panting, catching her breath.

I push her back a little and moved away from the edge of the pool. She moved in closer to me and jumped up and I caught her. Both hands grabbing at her tone ass, as I let her rest her bikini covered pussy on top of my cock. She leaned in and kissed me, and I felt her tongue explore my mouth and find mine. We kissed for what seemed like forever and I felt her grinding against my shaft. "I've got to have you now", I whispered in her ear. I could tell she felt the same way when she looked at me and I heard a soft "mmhhmmm". "Follow me", she said.

I looked over towards the grill and saw Allison watching over it, apparently Brian had gone inside. She was paying more attention to the grill, so I was able to follow Madison out of the pool, and not worry about my daughter seeing her dad with his face almost pressed into her cousin's ass as we got out of the pool and she led me over to the pool house.

We got inside and she closed the door behind us. I pulled her to me and reached around to cup her ass and pull her in close. I kissed her and untied the string on the back of her top, and let it fall away. Her tits were perfect, nice and firm and I leaned down to suck her nipples into my mouth. I heard her moan as I sucked on one and then the other nipple, making them nice and hard. I reached down between her legs and started to feel her pussy through her bottoms. I could feel the heat coming from between her legs. I tugged at the bottoms of her suit and as I got them over her hips, she let them fall to the ground. Her bald, teen pussy was there just begging to be fucked. She moved over to a bench and turned her back to me and bent over. "Fuck me from behind Uncle Marc, please fuck me now". I walked up behind her, pulling my still hard cock from my suit and holding the shaft aimed the tip at her tight pussy. I rubbed the tip of my cock along her slit, it was so wet and without further delay, I started to push it inside of her. We both moaned out loud, as I felt her tight pussy stretching around the shaft of my cock as I worked my way in and out of her. First the head, then inch by inch each time I pushed in until finally after I was halfway inside of her, I grabbed her hips, and plunged the rest of my length deep inside her. She cried out as I filled her gripping hole with my throbbing cock. I started to fuck her with long deep thrusts, loving how her pussy gripped my dick, and how I could feel it stretching around the girth each time I thrust inside of her. She was bucking back into me as I was fucking her, my balls slapping against her each time I buried myself inside. Our pace quickened and I felt her fingers tickling my balls as she started to massage her clit, while we fucked.

"I'm getting close", I said as I felt my balls tighten. I plunged deep inside of her as she cried out, "I'm cumming!" and I felt her pussy clamp down on my cock as the heat of her pussy juices coated my cock and dripped down onto my balls. I held my cock inside her as long as I could as her body calmed down from her orgasm. I then took a few more slow thrusts inside that hot wet pussy and pulled my cock out just in time as I started squirting my warm thick cum all across her ass. I let my cock glide between her ass cheeks as I pumped the final ropes onto her. I moved away and she turned around and dropped to her knees and started to suck my cock, sucking and licking the tip and tasting her cum as she slurped and licked along the length until it was nice and clean.

She stood up and reached onto her back and ran a finger through my cum and sucked it off her fingers. "That....Uncle Marc, is how a summertime cookout should start!" We both got dressed, and I watched as she pulled her bikini bottoms over her cum covered ass. We then opened the door and took a look out, only to see that Allison was walking out of the house in front of Brian, looking straight at us as we left the pool house. "Fuck, I mumbled under my breath". I'm pretty sure we just got caught by my daughter and brother-in-law I think to myself. "Don't worry Uncle Marc, it is all part of our master plan". She smiles and waves at Allison and bounds over towards her. Is that a look of satisfaction on my daughter's face?