“We Shouldn’t.”

“I know.”

“It’s wrong.”

“I Know.”

“We could get caught.”

“I know.”

“We would lose everything.”

“I know.”

Despite all the solid arguments she was making my hands continued to fondle her large, hanging breasts. They were being covered, rather than supported by the plain purple and black plaid one-piece swimsuit she was wearing. Between responses I buried my face into her black curly hair and continued to bite and nibble on her neck. Between her protests she moaned and gasped.

My own swimsuit was doing nothing to conceal my hardness as I pressed into her fleshy, ample bottom. I had been fantasizing about her since the day my wife’s loser brother introduced her. Over the years my feelings had grown more lustful.

She was too good for him, with long black curly hair, chocolate colored light brown eyes, the slightest hint of freckles, an adorable dimple, and flawless pale white skin. Her body was slender, yet curvy in all the right places. Her boobs were large, but not overly big and her hips framed an amazing ass. Since we first meeting I had been fantasizing about her.

After fifteen years she had changed. With three kids her boobs had gotten bigger, but with each subsequent kid they hung lower. Her belly was soft and plump, but proportionate to the rest of her body. Her thighs were thick and chunky and her ass was big and round. However, none of that changed how I saw her.

I always openly flirted with her and over the years the flirting had become more reciprocated. Whenever we were with family it remained innocent and playful, but in the rare instances we were alone it got fairly explicit and flat-out raunchy.

And now here we were. My wife’s parents rented a beach house for the family. For three days we spent basically all day playing on the beach and in the ocean. It wasn’t often that I got to see this much of my sister-in-law’s body and it was getting to be more than I could handle. It didn’t help that each time I made an inappropriate comment to her she responded with one of her own.

As I played in the ocean with the kids I noticed she got up and walked to the house alone. I quickly threw one of the older kids and headed on shore.

“What’s for lunch,” I asked as I walked up.

“Amanda just went in to make sandwiches for the kids, then we’ll all go out to lunch,” my mother-in-law responded.

“Ok, I’m going to go clean off,” I said hurriedly as I walked past everyone.

When I entered the house I went right to the kitchen. There Amanda stood at the counter, looking out onto the beach. As I watched her ass jiggle slightly each time she moved while preparing the sandwiches I got harder and harder. Finally I couldn’t take it anymore and quietly walked up behind her.

“Mmmm, this is a sweet ass,” I said as I placed my hand on her butt.

She turned around, startled, “Oh my god, Jim, stop that.”

“Well, you know it’s true, and you’ve been flaunting it in front of me for three days.”

“I haven’t been flaunting it, we’re at the beach you idiot, what am I supposed to wear?”

“Nothing,” I said laughing and reached to her butt again.

She playfully slapped my hand away, laughing. “You’re so bad.”

“You know you like it,” I joked back to her.

“Well, you’re just going to have to look at it, no touching,” she said, turning back to the counter and wiggling it for me.

That’s when I moved in closer, “Fine, I’ll keep my hands off.” I thrust my pelvis forward and my hard cock rubbed against the fabric of her swimsuit.

She immediately stopped what she was doing and dropped the knife and piece of bread. Instead of protesting or moving away she pressed her bum into me, making my cock poke into her even harder.

That’s when I took my cue. I reached around and took her in my arms, grabbing her big, soft breasts. My face nuzzled into her neck. As I kissed and nibbled on her neck while playing with her boobs she just coo’ed and her breathing increased.

After a few minutes the protests began, but they were merely for show.

Neither of us had any notion of stopping. Soon my hands found their way into the top of her swimsuit. I gently pinched at each of her nipples, making them harden. I took each nub between my fingers and gave a gentle twist while pinching. The whole time both of us were moving against each other so that we were dry humping through our swimsuits.

I cupped both of her boobs in my hands and took her nipples between my thumbs and forefingers. I pinched hard and said, “I have jerked off to these so many times.”

She just let out a slight sound, almost a whimper. I let go of one of her breasts, but kept the other in hand. My hand slowly moved down, over her swimsuit. Soon it found her pussy and she quivered as I placed my hand onto her covered mound. As I pressed into her soft pussy she pressed against my hand.

I let go of her boob and stepped back a little so I could slide my swimsuit down. With one hand I pulled it down. I took hold of my cock and started to rub it on her ass, leaving a trail of pre-cum wherever it passed. I took it and nestled it into against her ass, then down in between her legs. When it was there she grasped it with her thighs.

“Jim.”

“I know we shouldn’t,” I interrupted.

“No, it’s not that. Please fuck me before everyone comes back.”

That’s all I needed to hear. I pressed her forward so she was leaning over the counter, her face only inches from the window. I let go over her boob and my cock and reached to her ass. I know she said no touching, but I figured that rule was out the window. I grabbed one of her cheeks with one hand and the edge of her swimsuit with the other. As I pulled her suit aside and spread her ass I had a perfect view of her wet, pink pussy and tight little puckered hole. She had told me she shaved her pussy in one of our more graphic flirting sessions, but a few little black curly hairs were there, just accentuating the pinkness of her pussy.

As much as I wanted to stick my cock in her I had to taste real quick. I dropped to my knees, spread her ass and buried my face into the back of her thighs. My tongue slid right between her slippery cunt and my nose pressed into her ass.

I slid my tongue all the way up her slit as she moaned out, “Oh fuuuuuck,” then I stood.

I took my cock in hand, guided it to her hole and with one quick thrust I was inside her.

“Holy shit Jim, that feels so fucking good, please fuck me.”

I didn’t wait. Immediately I began to thrust into her. I started out hard and fast. As my stomach pounded against her ass it wiggled and bounced. My balls were swinging forward and slapping her cunt and her wetness was slurping with each thrust. I reached down and spread her ass so I could watch my cock bury into her and see her asshole clench with each thrust.

When I looked back up I said, “Oh shit,” but didn’t stop.

She looked up and saw the same thing I did, everyone was starting to gather up towels to come in for lunch.

I began to slow, but she begged, “Please Jim, don’t stop, just finish.”

Regaining my speed I thrust into her in a frenzy. We were both panting and grunting as everyone started to walk up the beach.

I grabbed her ass and thrust in as hard and deep as I could.

“FUUUUUUUCK!” we both yelled out as I shot my load deep into her pussy.

Unfortunately neither of us had any time to revel in the bliss. She immediately stood up and put her tits in her swimsuit.

“Hurry up, get out of here,” she said, in a sudden panic, realizing the precarious state we were in, now that it was all over.

I grabbed my swimsuit and dashed to the bathroom. Just as I heard the front door open I walked out. Amanda was still at the counter making sandwiches as if nothing had happened as everyone came in. Her husband walked over and kissed her on the cheek. She finished and stepped past him.

“I need to go clean up before we go,” she said, smiling towards me as I watched her walk into the bathroom.