Sister in Law Bacseat

This is my first story submission. Feedback and comments are welcome. Hope you enjoy.

Chapter one

It had been a great concert. Festival really. Five rock bands that my wife and I had loved when we were younger had reunited and were on tour playing stadiums, areas and, in this case a large grassy field about an hour from our home in Toronto.

When we saw the tickets go up we had snapped them up, picking up one for an old friend of ours and, surprisingly one for my wife's much younger half sister, Jenny.

I say surprisingly because while I am 40 and my wife, Kristen, is 39, her sister is from my father in law's second marriage and she is only 19 years old, not someone you would expect to enjoy a show of middle aged rockers and fans re-living their youth.

Not that I minded. My wife's sister is fun and funny and, honestly, pretty enjoyable to look at. She's 5'4 with thick curly brown hair, wide set eyes, a cute button nose with freckles dancing across the bridge and over her cheeks. She always seems to be smiling. Her small frame carries a full chest, (I would guess 36D? I dunno. I'm terrible at guessing these things) a relatively small waist and full hips and ass. I have to admit that I may have found my eyes inappropriately lingering on her body from time to time at family events.

This isn't to say that I had done more than that: look. I was happily married to a woman I find beautiful. Kristen has aged wonderfully. She has a full figure as well (my preference) and the slight crows feet around her eyes and the odd grey hair (which she promptly plucks out) are the only indications of her age. She gets asked for ID when purchasing liquor and most people assume she is in her late twenties not late thirties.

I suppose since I've been describing these women I should tell you about myself. My name is Mark. I've been told I'm handsome. Most people are surprised by my age as well, though I no longer get the guess of 25! I'm 5'11, and keep in decent shape. For a while I was building up a bit of a belly and love handles, getting a real dad bod, the result of long hours spent at work behind a desk, but I was uncomfortable with that so started running long distance. My blond hair is thinning, but I'm not bald. I have a full beard that is beginning to get steaks or Grey (which I kind of like).

I suppose the choice not to have children my wife and I made has contributed to our relatively youthful appearance. My friends who had families do not look like us. They look like parents.

Anyway, our friend, Bill, had volunteered to drive since he quit drinking five years ago and we were in his car on the way home. Kristen was in the passenger seat. She suffered from pretty bad road sickness sometimes and could not handle sitting in the back. She had the AC on high and was trying to fall asleep to combat this. I was in the back seat with Jenny.

"Can you turn down the AC?" Jenny asked rubbing her arms. It was a warm summer night, though now that the sun was down it had gotten much cooler, and she had worn a fun but not warm outfit to the concert.

I glanced over at her. Her top was a blue textured tube top that rolled over her full breasts, hugging under them and stopping just above her belly button. Her skirt was loose and came halfway down her thighs. I must admit that I had enjoyed watching her dance to the music earlier with my wife.

Looking at her now I noticed that the cold air in the car had made her nipples hard and they were tenting out the material. I tried to be discrete but marveled at how high her breasts still stood. Ah, the wonders of youth!

"Sorry," Kristen called back. "I need the cold air to keep my nausea down! It sucks I know but I can't help it."

"I have a blanket back there," Bill called back.

Jenny looked at the blanket that was on the seat between us and shrugged.

"Ok. Maybe later," she said off handedly.

Kristen seemed to fall asleep then and Bill, saying that he needed something to stay awake turned up the radio. Both Jenny and I were looking at our phones.

I was scrolling through Instagram, checking out the photos of friends, artists I like and funny memes. As I was flicking my thumb across the screen I heard Jenny say quietly, "Oh, she's cute."

I glanced up at her and saw that she had been watching my screen not hers. I scrolled back down and saw what she had referred to: a photo of a tattoo artist I followed, in this case wearing a cute top that showed off a pretty impressive set of tits.

"Does Kristen know you follow hot chicks?" Jenny teased.

"Hardly," I scoffed. "I think you'll find this pretty tame." It was true. I didn't really use Instagram to look at girls.

"Lame," she said smiling. Suddenly she plucked my phone out of my hand. "Here, let me show you something...my account...it's private so I'll have to approve your follow..." she handed my phone back and picked up hers, presumably approving my follow.

I was curious so I took a look. My eyes widened as I began to scroll through the feed of someone with the username @jennyhazfun88. All the pictures were of the same girl, in various sexy poses wearing various sexy outfits. And they were, of course, all of my sister in law.

"Uh," I stammered, unsure of what to say, what she wanted from me, why she showed me this. "It's..you?"

"Yeah" she said quietly. "It's like a fun, I dunno, project? What do you think?"

I should have closed the app. I should have said something non-committal, something appropriate. I should have. But I continued to scroll. Here was a picture of her, camera angled up at her, in a very small red bikini. Her pale skin like porcelain, the undersides of her breasts round and inviting. Another of her in the bath with bubbles covering her lower half and an arm draped across her chest, hiding her nipples but nothing else. The next one was of her laying on her back on a bed, wearing a thin babydoll negligee. Beside her, laid out in a fan formation were four dildos and vibrators of varying sizes. The caption read: busy night ahead of me!!

Now I am only human. I cannot help the fact that I am a man and I react to...certain stimuli. My cock, which had been contentedly resting flaccid between my legs, suddenly, and excitedly began to wake. I was wearing light, loose shorts (perfect for a hot summer day at a festival) and as I began to react, my cock filled, thickened and lengthened down there leg of the shorts lifting the fabric slightly. I glanced down and, while I could see clearly, I hoped that in the dark of the car Jenny wouldn't notice.

I coughed nervously and finally looked up, away from my phone and at her. She had shifted so that she was leaned back against the door behind her. She was watching me carefully, green eyes focused on my ice blue ones. I couldn't help but to scan her body, one o had seen so clearly in those photos.

I had noticed her nipples were hard earlier from the cold air. If I wasn't mistaken there were harder now. Making more of an impression against the fabric of her tube top. My eyes slid down further and saw that her skirt, either because of the way she had shifted or by design, had moved higher, revealing most of her smooth thighs. Any higher, I realized I would see her underwear.

I shook my head and forced my eyes back to meet hers.

"Um..."I stammered, unsure about anything at this point, "what...what the hell, Jenny."

She smirked and put on a false pout.

"What," she teased, "you don't like the photos?"

"Um...they are very nice...but why did you show me them?"

"Only nice," she asked, ignoring my question, pouting some more, though I could see her eyes dancing with mirth, "that's too bad. I thought some of them were pretty good."

"It's not...they are...yeah. They are good for what they are but...what the hell? Does Kristen know you have this account?" There. Remind her about my wife. Her sister. That should bring this back down to a more appropriate level.

"Kristen?" She chuckled. "Nope. No one who knows me knows that I do this. Just you. I guess it's our secret."

I didn't like the sound of that. I had been married for 12 years at that point and knew that secrets were terrible and almost never worth it.

"Well," I said. "Very nice and all but let's leave this at that." I was using a firm voice, the one I use with my staff when they are in need of some gentle guidance.

"Oh," she said, "but you haven't seen them all! Here, let me show you."

She was quick. Quicker than I was able to process what was going on. She unclipped her seatbelt and slid the very short distance between us, scooping up the blanket and putting it on her lap.

"I guess I do need the blanket after all," she said loudly to the car. I winced. Bill, who was nodding along to the music glanced into the rear view and gave a thumbs up. Kristen, to my horror stirred and glanced over her shoulder.

"Ya, sorry," she said sleepily. "Jenny, share with Mark. He won't admit he needs it but will wind up whining after we get home." Then she closed her eyes again and seemed to drift to sleep.

"Good idea," Jenny said and flicked the blanket across our laps.

She was pressed against me, her bare thigh (had her skirt ridden up any higher? I couldn't tell because of the blanket) pressed against my leg, skin touching skin below the fabric of my shorts. She was half turned so that her breast was pressed against my upper arm.

If my cock had been half hard before, it was now, almost painfully at full attention. I could smell her. A mix of a light perfume, the vaguely floral scent of her hair products, and below that the almost sweet musk of someone who had been out in the sun all day dancing and having fun.

"Let's look together," she said quietly, wrapping her small hand around my larger one holding my phone. "You can give me feedback. All I ever get are gross dudes in my DMs trying to get nudes."

She glanced up at me.

"Don't worry. I almost never send them any. Though," and she leaned close to whisper in my ear. Her breath was warm against my lobe. "I have plenty I could send them. If I wanted to."

My cock twitched at the feeling of that warm air on my skin, the words bringing to mind images of her naked. I was very glad that the blanket covered the bulge in my shorts.

"We really shouldn't," I said weakly. I had lost control of this situation by now. I was trying to keep this from getting out of hand but...was my heart really in it?

"It's fine," she said. "Don't think too hard about it. And speaking of hard..."

I coughed again, in shock this time as her hand darted under the blanket and suddenly gripped my cock through the material of my shorts. I looked at her quick with my eyes wide and shook my head.

"Don't," I whispered, moving my hand down to try and move hers.

"You don't," she whispered back. "Don't cause a scene."

She was right. I couldn't think of a way to fight her off without this becoming visible and then, who knows. Kristen would freak out. Bad blood between the sisters. And who's fault would it be? Mine. So, I just sat there, my sister in laws 19 year old hand wrapped around my cock.

"I just want to know what photos are the most...effective. So let's look and I can judge what you like." She gave my cock a quick tug and smiled at me.

"This is real nice," she said, voice low so that only I could hear. "My sister is sooo lucky."

I grunted non-committedly. I knew I had a decent cock. About 7.5 inches long and pretty thick. Not so big that it would terrify someone but plenty to fill someone...my wife! To fill my wife and no one else, I reminded myself desperately.

Jenny began to scroll through her photo feed and I watched the screen helplessly. There were a lot of photos. I wondered how long she had been doing this? As we scrolled through her hand was lightly gripping my length, not stroking but the heat and weight of it always there.

As we passed a photo of her kneeling on a bed, wearing only a chunky cardigan sweater tied at the waist. Her legs were open, the space where they met shadowed but the sweater but my imagination filled in the information that she was without panties. Both of her shoulders were bare as the sweater dropped off of them and it hung open, revealing the inside curves of her breasts stopping just shy of her nipples. My cock jumped when I saw this image and Jenny chuckled.

"You like that one?" She asked. She began lightly stroking my length. "The sweater does it for you?"

"Stop," I said weakly. She did not.

"I have a lot more photos from that session," she purred in my ear. "I couldn't upload them though. Instagram sucks and I don't want to get banned."

"Here," she said, dropping my hand and phone, and pulling her own out. I watched as she opened her photos and my eyes widened as I saw folder after folder of photos. She quickly found one and opened it and I saw her in her sweater. She did this all with one hand so she could continue to lightly stroke me.

"There we go," she said as she showed them to me. There was the one that got posted, but there were plenty more. Soon there was one where the sweater had fallen away and her full breast was on display, her nipple a hard light brown button with the circle of her areola around it. I grunted instinctually and she squeezed me making me sigh.

"Yeah, I thought these were sexy too," she said. "I got so turned on taking these photos. I was dripping wet. See?"

The next photo had her leaned back with her knees further apart. I could now see her pink pussy lips, completely devoid of hair, parted slightly.

"Look close," she said. "You can see how wet I was."

Sure enough there was a glisten on the lips. I swallowed hard.

"You shouldn't show me this," I whispered but did not take my eyes away from the image.

"I always get horny when I take the photos. I think of guys looking at me, jerking themselves. Like this..." she pumped my cock hard a few quick strokes. I could feel the foreskin of my cock slide across the swollen head, lubricated by my pre-cum. "And that's so hot, you know?"

She grinned at me.

"I'm wet right now."

She removed her hand from my cock and I sighed. It should have been from relief, but really it was from disappointment.

She gripped my wrist and pulled my hand towards her and placed it, palm down on her upper thigh. There are plenty of things I should have done but at this point..I was gone. I didn't care that my wife was a couple of feet away from us. That my marriage could end at any moment if we were caught. I just felt the young flesh under my hand and reacted.

Jenny was tugging on my wrist and I let her lead it higher. The smooth skin of her thigh slid under my hand, feeling like perfect silk under my fingers. I could feel the heat of her sex before my fingers reached it and I didn't notice that she had removed her hand from my wrist and I was moving on my own now.

Her legs were parted and my searching fingers met fabric. I lightly traced the edges of it, finger tip following first up one of the angled seams then down and up the other. I heard her groan softly as I did that.

My fingers returned to the fabric of what I could now tell was a g-string and traced across the fabric down to where it hugged the lips of her pussy, the source of the heat between her legs. I could feel how damp it was. She had not been lying. She was wet. Very wet. I pressed against the panties, pushing the wet spot between the lips, rubbing softly making her moan quietly against my ear.

In the meantime her hands had moved back to my lap. I was focused on stroking her sex so I didn't register as she popped the button of my pants and opened the fly. I felt her reach in and quickly and with skill pull my full hard cock through the front of my boxer briefs.

"Ohhhhh," I groaned quietly as she gripped me and began to stroke.

I moved my fingers to the side and pushed them under the fabric of her panties and pulled them to the side, exposing her pussy to the same air that my cock was feeling against it. I pushed my finger between her lips and rubbed across her clit making her hiss in her breath, along the velvet channel, finally to her opening where I hooked my middle finger and pushed it up into her hot wet cunt.

"Oh fuck, finally," she moaned into my ear and began to stroke me faster. I checked and confirmed that there wasn't too obvious movement in the blanket that covered us. We were relatively safe in that regard.

"You are so bad," she said, her voice husky now. "Finger fucking your sister in law right beside your wife!"

"Shut up," I hissed, not wanting anyone to hear us over the music that Bill had blaring. I pulled back my finger and added a second one before pushing back into her. I placed my thumb against her clit and she moaned again. Slightly louder this time.

"Or what?" She said, teasing. "Will you punish me? Like you are my daddy? Want to spank me daddy?"

I gritted my teeth and pushed my fingers deep into her while rubbing her clit with my thumb. No woman had called me daddy before and I'd be lying if I said it didn't make my cock twitch in her hand.

She moved her hand up and rubbed across the top of my swollen head and coated her palm with my pre-cum and then rubbed that down my shaft. Her hand left my sex and I groaned with disappointment but had to smile as she raised it to her mouth and licked my pre cum off of her.

"Tasty," she said before gripping me again.

We were keeping pace with one another now. As she stroked down on my rigid pole I'd push my fingers into her. As she pulled up I would pull back. And on and on, our breath heavy. I watched her face as we pleasured one another. Her eyes were half closed, her plump lips parted slightly. Occasionally I would glimpse her tongue dart out and run along them.

"Oh fuck," she whispered. "I'm getting close. Don't stop." I watched as she slid her free hand up her body, around the curve of her heavy breast, fingers finding her hard nipple which he began to pinch and tug.

"Grab my tit," she hissed. "Pinch me, daddy!"

I didn't need any more invitation. I had been looking at her young breasts for years and now was my chance. I placed my free hand, the one not fucking her with my fingers, over her other breast and squeezed, feeling the hard nipple against my palm. It was heavy as I lifted it, but firm, with next to no sag. My fingers found her nipple and I rubbed my thumb around it, rolling it. Then I pinched it between my finger and thumb.

"Oh fuck, daddy, yeah, just like that," she gasped.

She sped her hand on my cock and I matched her pace with my fingers inside of her. She was moaning quietly as I chased her climax. I was slightly worried about that but at the same time my own release was building.

"Oh," she gasped. "Oh, oh, oh..."

I could feel her inner thighs begin to quake against my hand and knew she was almost there. I sped up my fingers, a quiet wet sound coming from under her blanket at my fingers drove in and out of her sopping pussy. My thumb pressed hard against her clit and I pinched her nipple hard one last time making her gasp and then begin to squeak.

I released her tit and slapped my hand over her mouth, muffling the noise that was building as she began to orgasm. I felt the muscles of her cunt clamp down on my fingers and wished that I could feel that on my cock.

I continued to finger her as she created and then rode the wave of her climax, humping herself against my hand. She continued to grip my cock but was no longer pumping it. Now it was acting like an anchor for her to hold as she came. She was moaning against my hand, the sound muffled as I held her in place. Finally she tensed, her legs shooting out straight.

"Ohhhhhhhh fuuuuuuuck," she groaned against my palm.

As her climax subsided I kept my fingers in her, stroking slowly now as I brought her down from her crest. She was panting and I could see a glisten of sweat on her brow and across her chest above the tube top.