Becoming My Little Brother's Toy

I took the bag from Tristan dreading what I was going to find inside. Mom had announced that we were going to the beach for a family day out. I wasn't really in the mood for a family day trip anywhere, but when Mom decided something was happening it was not up for negotiation.

And, of course, a trip to the beach provided Tristan with the opportunity to buy me a new swimsuit. Last time he'd bought me a little red bikini that was 3 sizes too small. I was terrified of what he'd bought me this time, especially since our parents would see it.

I opened the bag and pulled out the contents. My eyes widened as I saw the tiny black bikini. The top was barely enough to cover my ample breasts, and the bottom was a thong that wouldn't leave much to the imagination. I could feel my cheeks flushing with embarrassment and anger as I looked up at Tristan.

"What the hell is this?" I hissed at him.

Tristan smirked at me, clearly enjoying my discomfort. "I thought you might like it. You know how much I love seeing you in revealing clothing."

"Yes, but Mom and Dad are going to see it as well," I reminded him.

"Well, you could always keep your clothes on if you prefer. And hey, it's not as small as last time," he said.

That was true. It wasn't as small as the red one had been, thank God. I shook my head and reminded myself that in just a few weeks our deal would be over and I would no longer have to do as he said. I'd be free.

I got changed into my new bikini and put on a pair of shorts and a tank top over the top before heading down to join my family as they loaded the car.

We'd been coming to the same beach since Tristan and I were little, so we knew the place well. There was a really secluded area just behind the caves that hardly anyone knew about. In all the years we'd been coming here we'd only seen 3 other people in the hidden beach area. Today when we arrived we found it as empty as usual.

"Okay then, let's get the grub!" Dad said, pulling out the blanket and unfolding it over the sand.

Mom and I started getting the food out of the bags and Tristan grabbed the drinks from the cooler. We sat down together and ate lunch, and as we laughed and joked as a family I forgot that I hadn't even wanted to come to the beach this morning.

"Right!" Dad said, standing up after we'd finished eating. "Time for a swim, I think."

"No, you can't swim after eating or you'll get a stitch," said Mom.

Dad pulled off his shirt and discarded it on the blanket. "Oh, no. A stitch. Imagine the horror," he said with a laugh.

"You won't be laughing when you do get a stitch, and you sink beneath the water, and a shark bites off your leg. And don't you dare come crying to me if that happens," Mom said, folding her arms haughtily.

I watched as Tristan followed suit, dropping his shirt to the sand and revealing his lean, muscular chest. I tried not to let my eyes linger too long on his defined abs and chiseled arms, but it was difficult. He noticed my gaze and smirked at me. It wasn't fair how attractive he was, and how much he knew it.

"Come on, sis," he said, gesturing for me to join them. "Don't be a party pooper."

I sighed, realizing there was no getting out of it. I took a deep breath and stood up, peeling off my shorts and tank top to reveal the little black bikini beneath. I held my breath and waited for the reactions from my parents.

"Erin!" Mom said when saw what I was wearing. "It looks like you left most of your bikini at home."

My face turned crimson and I wanted to cover myself again to avoid the embarrassment. Tristan smiled appreciatively, and I could feel his hungry eyes all over my body. "It's fashion, Mom," he said, saving me from having to think of a response.

"Fashion seems to have left all modesty in the past," said Dad, his eyes hovering over my breasts before hastily looking out towards the sea.

I refused to turn my back to them so they wouldn't see that I was wearing thong bottoms.

Mom decided to stay with the stuff having never really liked swimming in the sea. Tristan and Dad raced to the water and I trailed behind. With them in front Dad wouldn't see my bare backside.

We all waded out farther into the water, stopping when it came up above our waists. Tristan's abs were just visible underneath the water and my eyes lingered there for a moment too long as he turned and splashed me.

"Hey, look out," Dad said, splashing Tristan back for me.

Tristan laughed and ducked underwater before emerging again at Dad's side.

"I've got you now, old man," Tristan said as he grabbed Dad's leg and pulled him under the water.

"I beg--" Dad called out before he was submerged.

Dad burst into the air in a spray of water, gasping for breath as he tried to get the water out of his eyes. "You little shit," he said, laughing. He lunged for Tristan, but Tris darted out of the way, leaving me in the line of fire.

"No!" I squealed, as Dad collided with me, pulling me under the water in a big bear hug. I thrashed around under the water, trying to free myself and return to the surface. Dad got off me quickly and then his arms were around me, pulling me from under the water. I gasped for air as soon as I broke the surface, cradled in his arms.

"I wasn't going for you, Erin," he said as he laughed and gave me a small squeeze. That's when I noticed that one of his hands was on my ass, his fingers spanning an entire cheek. I looked up at my father's face but there was no sign that he'd even noticed where his hand was. I didn't dare move in case I made him aware.

"Yeah, yeah," Tristan said. "I thought it was hilarious."

Dad helped me back to my feet and just before he let go his hand gave my ass a little squeeze.

"Oh!" I said, looking at my Dad in surprise.

"What?" he asked, his face a perfect picture of innocent surprise.

"Nothing, Daddy," I said, smiling slyly at him and wading towards Tristan. There was no way that had been an accident.

"I want ice cream," Tristan said. "Anybody else want ice cream?"

"Me," I said. I hadn't wanted ice cream until he'd mentioned it but now I could picture the delicious ice cream cone in my head.

Mom and Dad didn't want any ice cream, so Tristan and I took off alone to the nearby ice cream stand. However, when we arrived we found it was closed.

"There must be a store nearby that sells ice cream. It's a beach after all," Tristan said.

"Yeah, maybe. I'm gonna go back and grab my clothes first though," I said. Walking along the bitch in my skimpy bikini was one thing, but going off the bitch dressed like this was out of the question.

Tristan grinned and shook his head. "I think you're fine like that, big sis," he said.

I laughed. "No way. I'll have, like, a heart attack. Seriously." He just smiled and shook his head.

"I don't think anyone's gonna mind if you go shopping in that outfit."

"I mind," I said, hoping that he wasn't going to force me, but knowing that was exactly what he was going to do.

"Too bad," he said. He slipped his arms around me and cupped my ass in both hands.

"Tris!" I hissed, trying to pull away.

He held me tight. "We're well away from home. Nobody knows us here." He planted his lips on mine and pushed his tongue into my mouth. I tried to resist but he was persistent and it was hard to fight back when I knew I wanted him. I yielded to him, pulling him closer so I could feel his stiffening cock against me. I pressed my hips forwards and tried to grind against him, but he laughed and stepped back out of reach.

"Come on, let's find some ice cream."

Reluctantly, I followed him off the beach and onto the streets of the town beyond. The farther from the beach we wandered the more looks from passersby I got. My face was a permanent shade of red as men and boys leered at me from all directions. Some of them made comments, I noticed one teenage boy actually taking a photo. I wanted to crawl into the nearest shadow.

"Do you have any idea how uncomfortable this is?" I asked my brother after one particularly long gaze from an older man.

"You love all the intention really. All these men checking out your big tits and plump ass. Wishing they could have a feel."

A part of me did enjoy knowing that so many men found me desirable, but that didn't take away the fear and embarrassment from the situation. And it didn't help the judgmental looks I got from many of the women who obviously thought I was nothing more than a slut. I couldn't really blame them since I was basically walking through town in my underwear. Nobody seemed bothered that Tristan was walking next to me in just a pair of shorts. Apparently, it was fine for men to dress how they liked.

We found a place that sold ice creams and headed inside. The storekeeper whistled when he saw me and leered over his counter. Tristan's presence did nothing to deter him even though it was obvious that my little brother could pummel the scraggly man if he wanted to.

We ordered the ice creams and as he handed them to us, he said, "I wouldn't mind if you wanted to stay here and lick them."

Tristan let out a great cackle of laughter before leading me away. As we neared the door Tristan leaned over to whisper in my ear.

"Flash your tits at him."

"What? No!" I said.

"Just once. Quickly. It'll be funny," he insisted.

"I'm not showing some creepy old man my tits, Tris," I said.

"I hate to be an asshole, Erin, but you don't have a choice. Do it, now."

I handed my ice cream to Tristan and turned around to see the old storekeeper was still staring avidly at me. My heart was pounding in my chest but not just from nervousness. I was excited too.

I grabbed my bikini top and yanked it up letting my boobs bounce free. The man's eyes bulged out of his head making him look cartoonish. I got a perverse thrill from exposing myself to him and I let them hang out for longer than I needed to. I gave the old pervert a good long look at the goods. The goods that he was never going to get his hands on.

"Well bless my old soul it's been a while since I saw a pair as big as those that didn't hit the floor when they were freed!" he said.

I blew him a kiss, tucked my tits away, and hastily left the shop. It was only a few minutes after leaving that I realized he probably had my tits on CCTV.

I was far less bothered by the stares I got on the way back to the beach. Pulling my tits out had given me a sort of immunity from the shame of it. By the time we reached the sandy dunes of the beach our ice creams were gone. We made our way through the throngs of people and back to the caves that concealed our little family hideaway.

As we neared our area I heard small gasping noises coming from the other side of the rocks. Tristan and I glanced at each other with our brows furrowed. We walked forwards more cautiously and soon heard manly pants as well as gasps. My mouth dropped open as I realized what the sounds were.

"That can't be," I whispered to Tristan, shaking my head in disbelief.

He strode forward to the small rock wall and peeked over the top. he turned back to me, his eyes wide with excitement, and nodded. "They're fucking," he said.

I walked over and glanced over myself, unwilling to believe his claim. Sure enough, Mom was flat on her back, her legs spread wide, and Dad was between them, panting away on top of her, thrusting his hips back and forth. They were both completely naked.

I couldn't help but notice Dad's cock. It was thick, straining, and pulsing with each thrust that he made. Mom's tits were shaking back and forth and she was moaning loudly in between her husband's deep thrusts.

"Holy shit!" I gasped, in shock at what I was seeing.

It was wrong. Absolutely immoral and disgusting to be spying on my parents this way. I should have walked away then, but I was aroused by it all. I felt my cunt getting wetter as I looked on.

"Your tits are bigger," Tristan whispered. He came up behind me, pressing his body against mine. He reached around and cupped my breasts in his hands, deftly pulling them free from my bikini so he could toy with my nipples.

"So is your dick," I said back.

He grabbed my hand, leading me to his bulge which was rapidly expanding beneath his shorts. I moaned as I felt him throbbing under my palm. It was so big that I couldn't even run my fingers all the way around it.

He undid my bikini top and pulled it away from my body. I watched it flop down to the sand and a moment later my bottoms followed it. Warm hair drifted between my legs, tickling my moist pussy.

I turned to face Tristan, slipping my fingers into his waistband and tugging his shorts down to his ankles. His gigantic cock sprung free and my heart raced at the sight of it. It truly was a specimen to behold. He stepped out of his shorts and his cock bounced with the movement.

"You've got the best tits I've ever seen, sis," he said. He pushed me back so I was leaning on the rocks, and stooped over to take my nipple in his mouth. I moaned as his tongue lashed against it. He sucked at me, biting softly and swirling his tongue around the pink sphere. The pleasure caused my cunt to pulse with desire.

As Tristan was licking me he reached down and began toying with my pussy, his fingers spreading my labia and slipping easily inside. I was already so wet that I knew a second finger wouldn't feel out of place. I moaned as he plowed into my cunt with two of his thick fingers, his thumb sliding over my clit with every thrust.

I looked over at Dad and Mom again. They were getting into it, Dad had put Mom's long legs over his shoulders and was fucking her violently. Her head was tilted back, mouth open in ecstasy as he humped away at her.

I mimicked her frantic gyrations, shifting my hips back and forth to get Tristan's fingers into me deeper. His tongue circled my nipple teasing me, making me moan and spasm with pleasure. When his fingers stopped their motions inside my pussy I sighed in disappointment.

Tristan spun me around so I was facing the rock wall and could see our parents fucking on the other side of it. I leaned forward, sticking my ass out, inviting him to take me. He needed no second invitation. His swelling cock found the entrance to my pussy quickly and he pressed himself inside.

"Ngh!" I grunted in surprise as he shoved forwards, my eyes growing wide as I felt the thickness of him spreading my cunt. He stuffed himself into me with one long thrust, his dick sinking in deep. I rocked back on him, feeling him pulse inside me.

"There's a good girl," Tristan said from behind me, his hands resting on my hips as he fucked me hard. I could hear Dad grunting and Mom moaning louder now.

"Oh!" I moaned, feeling his dick slide against my G spot. I pushed my ass back against him, eager to get all of him. All at once everything felt good. The pleasure of viewing my parents fucking only a few feet away, the sensation of my pussy being used by a large cock. To top it off Tristan's lips kissed the back of my neck, gently biting and licking.

I thrust my ass against him, rolling back and forth, pistoning his cock in and out of me. He grabbed my hips and responded with another swift, forceful fuck. Each time he filled me with his uncut length it pressed against my G spot and sent a wave of pleasure rolling through my body.

I was a horny slut just wanting to be fucked, and it felt so good to fuck Tristan that I almost wished that our parents could see. A small, horny part of me wanted to moan so loud that they both looked over. But I didn't allow myself to give in to that desire.

Tristan swelled inside me, his cock throbbing and expanding as he pumped me roughly. My cunt stretched and shifted to accept it all. He started grunting angrily, his thrusts becoming rougher and more passionate. He was going to cum soon, and so was I.

I reached back to squeeze his nutsack which was resting beneath his generous dick. It was so large I could barely wrap my hand around it, let alone get my fingers on the other side. I squeezed it playfully as he fucked me harder.

"Oh fuck," Tristan grunted from behind me. His knees buckled slightly but he caught himself on the wall. I could tell that he was holding off cumming, but no longer had complete control over it.

Mom and Dad's moans were getting louder and more frequent as their orgasms approached. "Fuuuuck!" She moaned, her hand disappearing beneath her and rubbing her clit. "Make me cum!" She begged.

"She's just as slutty as you are," Tristan said, reaching around and grabbing my swinging tit. He squeezed it hard, pulling on the nipple and causing me to moan.

"I know," I said, planting my hands on the wall to push myself back into his thrusting, fat dick. "Come on, cum in me!" I begged.

With his spare hand, he spanked me hard on the ass, sending a shiver through my body and causing a rush of pleasure to wash through my pussy.

"That's a good girl," he said, smacking me again. I lowered my head and sunk my fingers into the wall, bracing myself for the quickening tempo of his thrusts. I wanted to feel his cock more fully than before.

"Come on! Come on!" I moaned, eager for his cock to fill me with his warm seed. At once I felt something building inside me, an orgasm ready to be let loose. It was going to be a big one, I could already feel it. He fucked me savagely, slamming into me with renewed fervor that caused my insides to get wetter and wetter.

"Yeah," I grunted, "Come on, little brother!" He spanked me again as he pounded his cock into me.

Tristan grunted, "Give in to your lust, sis." His hand spanked me again as he humped me with renewed vigor. I could feel his prick swelling inside my pussy, a sure sign of his impending orgasm.

On the other side of the wall, Mom shrieked as her orgasm flew loose. Dad gave one last grunt before he pushed his cock all the way into Mom and stayed there.

That was enough to send me over my orgasmic edge. I pushed back against Tris again and again, grinding my ass against him, my pussy growing more and more wet as his cock stroked my G spot.

"Oh! Fuuuuck!" I grunted, my body starting to convulse.

Tristan's hands gripped my hips and he fucked me harder than he ever had before. He slammed, and slammed, and slammed, his dick slamming into me like a battering ram. I felt his cock spasm as the first burst of his cum squirted into me.

"AHHH!" I screamed out as I orgasmed. It started in my pussy, which sent a shiver through my entire body before it exploded into a full-on convulsion. My back arched and I threw my hair over my shoulder. My wetness squirted out onto the sand below me as wave upon wave of pleasure rocketed through my body. I threw my ass back against Tristan hard enough to knock him off balance, but he managed to stay on his feet, one arm holding him upright using the wall.

My breasts shook with the force of it all as it washed over me like a tidal wave. I could hear Tristan's grunts above it all, and when my body finally started settling down I realized that he was still fucking me, and hadn't stopped. He continued pumping his cock in and out of me, filling me with cum.

"What was that?" Dad said.

Tristan and I both hit the ground fast before either of our parents could see us. Silently, we snatched our clothes off the floor and bolted toward the caves. Once inside, we collapsed into exhausted laughter, our bodies slick with sweat, and both our juices running down my thighs.

I rolled on top of my brother and shared a tender kiss with him, grinding my sticky cunt against his shrinking cock. His dick hardened again in a matter of seconds and I rode my brother on the floor of the cave. The sounds of our lovemaking were stolen by the waves and carried out to sea.

When we returned to the beach our parents were dressed and chatting away like they hadn't been fucking just a short while ago. Tristan and I acted ignorant to what we had seen and our parents were none the wiser to what we had done. Twice.