This is the second part of the 'Helping out girlfriend's sister' series. You don't really need to have read the first part to follow the story. But you might enjoy the build up a bit better if you decide to go through that one first.
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I was half asleep. Curled up on my side in bed, drifting off. Exhausted from the day.
Jess, my girlfriend's sister, had left only a few hours earlier. She'd spent the day with me, practising her massage techniques for her professional course, while my girlfriend Jen was at work. She wasn't due back till close to midnight, so it had just been me and Jess all day.
I had fully expected to be just a 'body' for Jess to hone her skills on. What I hadn't expected, was for her to have forced me to help with some other skills.
Ones that left me both mentally and physically drained.
I tried not to think about her curvy, naked, tattooed body, covered in massage oil as I now laid in bed. Her large, bouncy tits as she shook them in my face. Her big, shapely ass that clapped as she rode me. I couldn't deny that I enjoyed thinking about her. But I immediately felt guilty for what I had allowed to happen to me.
And what I had done later that afternoon.
Yes Jess had been adamant about using me. But I hadn't put up much of a fight to be fair. And my cock had seemed more than willing to oblige her. I knew it was wrong. But God it felt so good.
All these thoughts were getting me hard again. Fuck, what was wrong with me?!
Just then, I felt a hand cup my ass. Giving it a squeeze, it slowly drifted over my hips and rested on my cock. And then started to lazily rub the tip of my head.
"Someone's in a good mood," a familiar voice whispered behind me.
It was Jen. When did she get home and climb into bed? I must have fallen asleep at some point. Maybe the blowjob I had hinted at when she left for work was about to happen? But even as she continued to softly stroke my cock through the fabric of my boxer shorts, before easing it out of the opening and taking it in her hand, my mind went back to earlier that afternoon. After Jess had just ridden me to an oily, wet explosion.
***
Jess was bent over, her ass in the air and my cum dribbling out her pussy, down the top of her thigh. She was rummaging again in her bag. I was still sat on her massage table, my cock semi hard but my balls now empty. I was looking at the glorious sight I'm front of me.
She looked round, her big ass still facing me and saw me looking. She smirked. Then as she was searching in her bag, she shook her ass. Her big ass cheeks wobbled and slapped together, ripples moving with each twerk.
My cock twitched.
Still shaking her ass, Jess pulled a hand out of her bag and spanked herself. Once. Twice. Three times. I couldn't look away. Each slap sent shockwaves across her cheeks.
My cock twitched again and started to grow.
Jess stood up, in all her tattooed, curvy, naked glory. I had gotten to know some of these tattoos up close and personal. Especially those she didn't usually have on show. As she walked over to me, I realised I hadn't really thought of them as a turn on in general. Plenty of women had them and they didn't really do much for me. But God, I'd never be able to look at Jess's ever again. They were ticking all the right boxes. And stirring all the right sensations.
She towered over me. She reached out and gently caressed my cock. I winced, still sensitive having just cum ten minutes earlier.
"Well, seems someone's ready for round 2," she smiled, slowly jerking my cock.
I moaned in response. After a few more strokes, the worst of the sensitivity was gone. Replaced with my rock hard cock, ready and willing to do whatever Jess asked. Or demanded.
The guilt of what I was doing to Jen though washed over me. I'd never cheated on anyone before. And here I was, doing it for the first time, quite literally, with my girlfriend's sister. I tried to shift away, my cock betraying the shame I was feeling. I knew that nothing could happen again. I had to put a stop to this. I pulled my cock away from her grasp.
"Jess, we can't do that again. It's not fair on Jen," I said, trying not to look at the inked goddess standing in front of me. "What we did was wrong."
Jess grabbed my cock again and smiled. A wicked smile.
"Was it really that wrong?" she purred, slowly stroking me. "You think we just end it here? You get to come inside me and then call it quits?"
She squeezed a little harder and stroked a little faster.
"You drool over my ass as soon as I walk in here. Get hard while I'm massaging you." She was getting louder with each sentence. Punctuating what she was saying with stiff, hard jerks.
"You take off my clothes. Lick my ass, beg me to fuck you and cum in my pussy? Then say it was all a mistake?"
She squeezed my cock in a vice like grip. All sensuality had now disappeared in her hand job. She was tugging angrily.
"Jess, you're hurting..."
"I just came over to get some massage practise in. Pass my course. Start a new career."
She took my balls in her other hand. Then gave them a full on squeeze. I yelped out in pain.
"But you. You got what you wanted and then go to throw me out like a dirty old tissue?"
"It wasn't like that,"
"Fuck. That."
"But you came on to me. I..."