I Walked In on My Sister's Boyfriend. Then I Went Back

The hallway was quiet as I crept toward the bathroom, the need to pee stronger than my better judgment. Michael, my older sister Jenny's boyfriend, was staying with us for the weekend, and I'd been trying to give them space.

Without thinking, I pushed the bathroom door open and froze. Michael was standing at the toilet with his back to the door, but the mirror gave me a perfect view of his front. And what a front it was.

His cock was enormous, thick and long even in its semi-hard state as he shook off the last drops. My breath caught as I stared, completely transfixed by the size of it. I'd seen a few cocks in my twenty years, but nothing that came close to this.

Michael turned sharply, catching my reflection in the mirror. "Emma!" he said, trying to cover himself with his hands.

I slammed the door, heart hammering as I leaned against it. I couldn't get the image out of my head. Michael's enormous cock, the way it looked in his hands as he tried to hide it.

"Sorry!" I called through the door, voice shaking. "I didn't know you were in there!"

"It's fine," he replied, muffled. "Give me a minute."

I hurried to my room, closed the door, and leaned against it, replaying the image in my mind. I'd always found Michael attractive, tall and muscular, dark hair and sharp blue eyes, but seeing him like that had woken something up in me.

My hand slipped between my legs while I imagined what it would feel like to have a cock that size inside me. I closed my eyes, picturing his body, his strong arms, his broad chest, and of course that cock.

I slid my hand into my underwear, fingers finding my already wet folds as I started touching myself. I imagined his hands on me, those big hands exploring my body while he prepared to push inside me with that impressive length.

The thought of being stretched by him, filled completely, sent a shiver through my whole body. I quickened my pace, breathing picking up as I got closer.

Right as I was about to tip over the edge, I heard Jenny's voice in the hallway. "Emma? You there?"

I yanked my hand back quickly, face burning as I tried to compose myself. "Yeah, just getting ready for bed."

"Okay, Michael and I are watching a film downstairs. Want to come?"

I hesitated, knowing I shouldn't, but unable to resist the chance to be near him. "Sure, be down in a minute."

I tidied myself up quickly and changed into a pair of short shorts and a tight t-shirt before heading down. Michael and Jenny were curled up on the couch with a blanket over their legs, the movie already going.

"Hey," I said, settling into the armchair across from them.

Michael glanced over at me, eyes lingering for just a moment before returning to the screen. I could feel the tension between us, the unspoken acknowledgment of what I'd seen in the bathroom.

As the film went on I found myself watching him more than the screen. I could make out the outline of him through the blanket and my imagination was filling in everything underneath.

Jenny fell asleep eventually, head resting on Michael's shoulder, breathing evening out. Michael shifted carefully, trying to get comfortable without waking her.

I caught his eye and smiled slightly as I stood. "Getting some water. Want anything?"

Michael shook his head, eyes following me as I headed to the kitchen. I took my time, knowing he was watching, before coming back.

When I passed the couch I "accidentally" brushed against Michael's leg, my hand lingering a beat longer than necessary. I felt him tense at my touch, a quiet sound escaping him.

I settled back into the chair and crossed my legs, keeping my eyes on him. I could see the conflict in his face, desire mixed with guilt as he tried to stay loyal to my sister.

The film ended and Michael carefully extracted himself from under Jenny. "Should head up," he whispered, glancing at me.

"Goodnight," I replied, voice low and deliberately suggestive.

Michael hesitated for a moment before heading for the stairs. I waited a few minutes before following, heart picking up as I went.

I quietly opened the guest room door where Michael was staying and found him sitting on the edge of the bed with his head in his hands.

"Michael?" I said softly.

He looked up, eyes wide. "Emma? What are you doing here?"

I closed the door behind me and locked it before moving toward him. "I can't stop thinking about what I saw earlier."

His face went red as he stood up. "Emma, you shouldn't be here. This is wrong."

"Is it?" I asked, stepping closer. "Because it doesn't feel that way to me."

I reached out and placed my hand on his chest, holding his gaze. "I know you want me, Michael. I saw how you were looking at me downstairs."

His resolve was crumbling as my hand slid lower, fingers tracing the outline of his hardening cock through his trousers. "We can't," he whispered, even as his body responded to my touch.

"We can," I said, dropping to my knees in front of him. "And we're going to."

I undid his trousers quickly and pulled them down along with his boxers. His cock sprang free, even more impressive than I remembered. Thick and long, the head already glistening.

I wrapped my hand around him, fingers barely closing around his circumference. I leaned in and let my tongue dart out to taste the drop at the tip.

Michael groaned, hands tangling in my hair as I took him in my mouth. I could only manage half of him, but I made up for it with enthusiasm, tongue circling the shaft as I moved my head up and down.

"God, Emma," he whispered, hips pressing forward slightly. "That feels so good."

I smiled around his cock, satisfied with his reaction. I kept going, hands stroking what my mouth couldn't reach while he got harder still.

After a few minutes Michael pulled me up, his lips crashing onto mine as he kissed me deeply. His hands moved over my body, squeezing my breasts through my shirt before sliding underneath to cup them directly.

I moaned into his mouth as he pinched my nipples, the sensation sending sparks through me. I could feel my underwear getting wetter by the second.

Michael broke the kiss, eyes dark as he looked at me. "I want to be inside you, Emma."

I nodded eagerly, pulling my shirt over my head and unclasping my bra. His hands were on me immediately, mouth closing over one nipple while his fingers worked the other.

I arched my back, fingers running through his hair as he attended to my breasts. I could feel his cock pressing against my thigh, hard and ready.

Michael lifted me effortlessly, carried me to the bed, and laid me down gently. He pulled my shorts and underwear off quickly, eyes moving over my naked body.

"You're so beautiful," he said, voice thick.

I spread my legs and invited him in as he settled between them. He rubbed the head of his cock through my wet folds, teasing me before slowly pushing inside.

I exhaled sharply as he entered me, his size stretching me in a way I'd never felt before. There was a slight ache, but it was quickly eclipsed by pleasure as he filled me completely.

"You okay?" Michael asked, voice careful.

"More than okay," I whispered. "Don't stop."

He began to move, slow and deliberate at first before picking up the pace and intensity. I wrapped my legs around his waist and pulled him deeper, meeting his thrusts.

The room filled with the sounds of what we were doing, skin on skin, moans and sighs, whispered words of want and encouragement.

I could feel myself getting close, body tensing as the pleasure built to an almost unbearable level. "Michael, I'm close," I breathed.

"Let go, Emma," he urged, thumb finding my clit and rubbing in circles. "Come for me."

That was all it took. I cried out as the orgasm hit, body shuddering around his cock while waves of pleasure moved through me.

Michael followed shortly after, thrusts turning irregular as he reached his own peak. With a deep groan he pushed all the way in, cock pulsing as he filled me.

We collapsed onto the bed, breathing hard as we recovered. Michael rolled to the side and pulled me into his arms.

"That was incredible," I said softly.

Michael kissed my forehead, expression conflicted. "Emma, we can't do this again. Jenny..."

"I know," I interrupted, though I didn't really mean it. All that mattered was the incredible sex we'd just had and the possibility of more in the future.

We lay in silence for a few minutes before Michael spoke again. "You should go back to your room before Jenny wakes up."

I nodded, reluctantly climbing out of bed and gathering my clothes. I dressed quickly, gave Michael one last kiss, and slipped out of the room.

As I crept back to my bedroom I couldn't help but smile. I'd gotten exactly what I needed.