Confessions of a Bad Boyfriend

Chapter II - The Sexy Sister

I was still feeling guilty for my naked fun times with sexy Sophie during fresher's week the first time I met my girlfriend's younger sister, Erin. She was an 18 year old sixth-former and had come to visit during half term to catch up with Sarah, and so she and I could finally meet and get to know each other a bit better. Little did I know just how well we were going to get to know each other that week...

Sarah had asked me to pick her up from the station in her car whilst she finished up some uni work. Now I'd seen pictures of Erin before so I knew she was attractive in a rock chick kind of way. Like Sarah she was a petite and pretty brunette, unlike Sarah she had tattoos, a streak of pink in her hair and a nose ring. What I wasn't expecting as she jumped into my car and introduced herself, was the instant chemistry between us. Every time I met her big blue doe eyes that night, it was like a jolt went through my body.

A couple of days after picking her up, we were all at a house party at Sarah's and this is where things started getting interesting. My girlfriend dressed in jeans and a sensible top, her sister dressed in a tiny plaid skirt, knee high boots and a leather jacket. All night she laughed at my jokes, held my gaze and kept dragging me outside to have a cigarette with her so we could flirt, with Sarah safely out of earshot. At one point I squeezed her arse and told her how 'fucking hot' I thought she looked. She loved it.

At the end of the night, after everyone had left Sarah went to get changed into her pajamas and her housemates drifted off to bed, leaving Erin and I alone. 'Cigarette?' she asked, her eyes sparkling and a naughty smirk on her lips. I knew the second we were outside we'd be all over each other and I couldn't wait. The fact this teenage babe fancied me enough to mess around behind her sister's back had my ego doing somersaults. Unfortunately, my girlfriend chose that moment to call out and ask me to come upstairs and help her with something. Game over.

For the next few days, whenever Erin and I were together, you could cut the sexual tension between us with a knife. Sarah was always around so nothing happened beyond flirty glances and the occasional sneaky grope. At the time, I was amazed she didn't notice anything but I've since learnt she's pretty oblivious to my interest in fucking other women. By the time the final morning of her visit came around, it didn't look like we were going to get the chance to get down and dirty, but thankfully, my girlfriend came to the rescue.

The three of us were sat on the sofa in Sarah's living room watching trash morning TV. Neither Erin nor I were dressed yet; she looked damm fine in a black t-shirt and tiny little pink knickers. I was sat between the two girls and the feel of Erin's bare thigh lightly brushing mine was all I could concentrate on. Sarah realised she needed to return a few library books that morning and asked me to keep her sister company whilst she popped out, kissing me on the cheek as she left.

I couldn't believe my luck. The second the front door closed, Erin straddled me and we started making out furiously on the sofa, my hands finally all over her sexy little body. We had 20 minutes. I pulled her t-shirt up and started sucking on her perky tits, but she interjected. "No time, I want to ride you senseless before my sister gets back," she whispered. Without skipping a beat, I lifted her up so she could pull down my shorts. My dick was already rock hard. She slid her knickers aside and gently lowered herself back down, moaning as I sunk into her.

Her pussy was soaking wet and it felt incredible as we started to move our hips in unison, her lips on mine. "Fuuuuck, I've been waiting all week for this dick," she moaned softly in my ear. She was so light, I could easily bounce her up and down on my dick and we were properly going at it. The whole situation was driving us both over the edge and I knew it wouldn't take us long to come. "Talk dirty to me," she demanded. "You're such a fucking slut, screwing your sisters boyfriend," I whispered. "You love it, you fucking stud" she replied, pressing her body into mine as we fucked. "I wanted you the second I saw you," I told her, not untruthfully. "Don't stop, I'm coming!" I grabbed her face. "You're so much hotter than your sister," I moaned, as Erin screamed out, "Yes! Yes! Yes!" in orgasmic pleasure, cumming hard all over me and the sofa.

She slid off of me and I threw her onto the sofa, standing up. She barely had a chance to breathe before I slid my dick into her mouth. "Oh god," I moaned. She was amazing, her hands expertly fondled my balls as she blew me. I could hardly believe my luck. There was no way Sarah could compete with this slutty sixth former, and she knew it. "You feel amazing," I was close to blowing my load, trying to hold off as long as I could to prolong the pleasure, "fuck, you're so good at that." Her hand found its way to my arsehole, and she started gently stroking me with her finger. I looked down at her pretty face as I came into her mouth. "Fuck, fuck, fuck." I screamed as she swallowed every last drop of my cum, looking up at me with a naughty glint in her eyes.

Coming back down to reality, I looked at my watch. We had less than five minutes til Sarah would be back. I pulled her up on to her feet and we kissed, passionately. "Fuck, that was so hot," she purred. "We better clean up," I replied, reluctantly breaking apart from her. Erin grinned at me and slid her tiny knickers down her sexy legs, before pressing them into my hand. "Something to remember me by til next time," she said, winking as she flounced off to the shower. I stood staring, dumbfounded as her now naked arse disappeared from view.

Luckily, Sarah didn't suspect a thing when she got back. Erin was as cool as a cucumber as we drove to the station to drop her off, happily chatting away to her sister as if she hadn't swallowed my cum that morning. As we gave each other a quick hug goodbye, Erin looked into my eyes with a smirk on her face and said, "thanks so much for having me, Matt." Truly, the pleasure was all mine.