The Sister in Law Back Up Plan

** This story contains consensual family sex in a total fantasy world where it is permissible. I do not give permission to re-post or archive my stories. All characters are 18 and over. This story has lots of dirty talk, straight sex, a bit of lesbian and anal sex - but real love too <3. Hope you enjoy. LR **

I was making an effort to be extra romantic this year and had booked a posh restaurant table for our anniversary. Me and Lorna had been together now for seven years, married for five.

Lorna was a nurse, and we had met randomly at a party back in the day. I admit the nurse thing was a turn on, and I was one of those guys for whom something about the uniform got me all hot and bothered. Turned out the reality was somewhat different. The last thing any actual nurse wanted to do was come home, and keep the uniform on to keep their man happy, or wear a sexy version on their off days.

Nevertheless we had a good sex life, and I loved Lorna with all my heart. She was blonde, smart, pretty, with a decent pair of legs, a good sense of humour and nice if not big tits.

But being with someone who did shift work came with its own challenges. My own 9 to 5 job (IT systems analyst if you want to know, as boring as it sounds) meant that sometimes we were ships that passed in the night, or indeed sometimes the early hours. We had to book date nights carefully - which came with two meanings. Date night type A was actually going out somewhere; cinema, restaurant, that kind of thing. Date night type B meant an early night and reliably good sex.

The first flush of any relationship is the most exciting I think, and so it was for sex. In those early days, Lorna had actually indulged my mild nurse fantasy from time to time. The most memorable time was when I had picked her up from a late shift in the early hours and she had given me a blow job in the car park, having taken my temperature and determined I was running a fever, the cure for which was making me come in her mouth apparently.

Occasionally I was away on business and stayed with her sister Stacey overnight to split the onward journey. The firm had a regional centre close to Stacey plus a concentration of work sites. I usually tried to schedule this when Lorna had a run of nights so that we wouldn't have seen much of each other even if I'd been working at home or the office.

Stacey was a single mom to two little girls, now aged 5 and 7. Deadbeat Dad wasn't in the picture much and barely saw his kids. Lorna and Stacey's folks were well off and helped Stacey buy the house and sort out all the legal business with her ex. They had never been married so that made things easier.

I don't know if it was the mom thing, the sister in law thing, or Stacey's curvy figure or all of the above, but I had had many fantasies about taking her to bed, sometimes with Lorna as a threesome and sometimes just the two of us. They were just harmless thoughts - I would never act on them.

In those fantasies I would hug my sister in law at her door, then strip her in the kitchen, bend her over the table and fuck her senseless, bouncing into her delicious ass, and finishing with her on her knees and me coming all over her face and naked tits.

Sometimes when Lorna and I screwed I would imagine it was Stacey underneath me. I came particularly hard when I did indulge that fantasy. It wasn't that my wife didn't turn me on still, she did. It was Stacey's big tits I craved.

Over the years of visiting Stacey with Lorna, and on all my overnight stays in the spare room, we had become close as family, and sometimes stayed up late chatting. I had grown to love her as a sister in law but I'd be lying if I said I didn't still spend time thinking about how her bare breasts would look or whether she had a shaved or hairy pussy. Those were not the thoughts a brother in law should be having but I couldn't seem to help myself.

So when Lorna had to change shifts at last minute and couldn't make our anniversary night dinner, it was her who had suggested Stacey be my back up rather than reschedule. I was disappointed of course, as I'd wanted to spoil Lorna and had had been looking forward to a type B date night.

But there was a part of me that was looking forward to spending time with Stacey. She could be somewhat anxious and intense, and was always worrying unnecessarily about whether she was a good mom or not. But she also had a good sense of humour and was sharp and intelligent.

Also, more shallowly, I wondered what Stacey would wear for our 'date' and hoped for a dress which showed plenty of her ample cleavage.

The Red Vine restaurant was half way between our places. It was quite posh in the pictures, had good reviews, and I'd had to book it a month in advance.

Fortunately, Stacey's mum and dad had been able to take the kids overnight at their place so we were all set. I'd stay in the spare room as usual, then head back home to meet Lorna.

I sat waiting in my car in the restaurant's small car park and waited for my sister in law's 4 x 4 to turn in. She spotted me, and pulled up one space over from me.

I got out and saw her check herself in the driver's mirror before opening the door. A long bare leg ending in a black strappy high heel came out followed swiftly by the rest of her.

I knew I was staring but couldn't seem to tear my gaze away. Stacey had gone all out tonight and looked sexy and sophisticated. She was wearing a spaghetti strapped black cocktail dress with a V neckline. Those beautiful big tits I sometimes dreamed about were partly on display, with a cleavage that gave me all sorts of wrong ideas. She had curves for days and her makeup had that strong evening look - the smoky eye shadow thing really did it for me. Her warm red lipstick emphasised the fullness of her lips.

She had her brown and blonde highlighted hair pinned up with little curly ringlets framing her pretty face.

Basically, she was smoking hot. This is my sister in law, I reminded myself.

'Wow, Stacey, you look amazing,' I said, leaning in to kiss her soft cheek. The delicate scent of her vanilla perfume filled my senses.

She laughed and slugged me on the arm.

'You scrub up well too, Adam.'

I was wearing a casual jacket and trousers with a smart shirt, the kind that worked without a tie.

She hooked her arm through mine.

'Shall we?'

***

By the time we got to dessert we had both had a few glasses of champagne and were a bit tipsy.

I watched as Stacey forked a piece of chocolate cake into her mouth and moaned. The sound went immediately to my cock and I imagined it was me in her mouth and not cake. Then I thought of her licking chocolate off my hard on. I had been battling an erection for most of the evening.

It hadn't helped that when Stacey went to the ladies after our main that I could watch her juicy ass sashaying across the restaurant without being caught. The black clingy material of her dress was stretched nice and tight across her rear and I speculated whether she had panties on underneath. There were no visible lines at all. That made me think of her mommy pussy. Was she bare just a few feet away from me?

She's your sister in law, I reminded myself again.

But I realised then I was at least a little in love with Stacey too. As well as dirty thoughts over the years I had also entertained romantic feelings too I guess. She brought out the protector in me. It was hard for her bringing up the kids as a single mum, I admired her and respected her, and I sometimes had thoughts of what my life would be like if I had asked her out and not Lorna all those years ago. I had once imagined being comforted by Stacey after losing Lorna in some kind of accident. After a few months of suitable grief, we would comfort each other in bed.

Lorna and I had tried to get pregnant and had just finished a second round of IVF without results. It hurt and had placed a strain on our relationship but we loved each other and would get through. But there was something about Stacey being fertile and having brought two kids into the world that made her more womanly than Lorna, more mature somehow, even though she was actually two years younger than Lorna.

I was a terrible person to be even having these thoughts, I knew.

'Penny for your thoughts? You look miles away.'

'Sorry, Stace. I was just thinking about Lorna.'

She looked momentarily hurt, before smiling and covering my hand with hers across the table. Her fingers were warm and soft. I felt a pleasant spark with the contact.

'It sucks she has to work tonight,' she said. 'But her loss is my gain.'

She squeezed my hand. Was she flirting with me?

My gaze dropped to the creamy curves of her big tits, beautifully pressed together as they were, straining against the fabric. Were her nipples hard or was it just the clingy material?

'Eyes up here, buster.'

'Oh god, I'm sorry Stace. I just...sorry.' I was mortified.

She laughed. 'I'm flattered, honestly. And I did put this dress on after all. I guess I've not exactly hidden them away tonight, have I?'

Heat went to my face. And lower down as well. Now I imagined those beautiful breasts in my hands. Not for the first time, to be honest.

'Well it's a great dress, that much I can say.'

'Very diplomatic. And thank you. It's been a long time since I've had reason to get all dolled up.'

Her smile was warm but I thought there was a hint of sadness in her eyes.

'No-one special in your life at the moment?'

She played with those pretty little honey coloured twists of hair around her face. She really was beautiful tonight, her blue grey eyes popping with the makeup. But to be fair, she looked good in a zip-front sports bra and leggings too, with no makeup - another image of her I had wanked over.

'Not unless you count the kids. I don't have much time, and most guys aren't interested once they know I'm a single mum.'

'Those guys are idiots.'

Now I got her full wide smile which was impressive.

'What a charmer. I can see why my sister locked you down.'

It was my turn to laugh now.

We were definitely flirting with each other. It felt risky but it was also the most fun I'd had in ages. Lorna was very much on an even keel, whereas Stacey could go from one extreme to the other. When Stacey wasn't anxious, she was a really great person to be around. I ordered us another bottle of champagne. We could pick up the cars later.

***

By the time the cab dropped us off at hers, we were both beyond tipsy and we giggled as she unlocked the door and practically fell in. I had sat in the front of the cab but had spent time glancing at Stacey in the back who had caught me looking several times.

I followed her through to the kitchen and stood behind her as she put the kettle on. Again my eyes dropped to her ass and I had the urge to hug her from behind, bury my face in her pretty neck and cup those big boobs. How would she respond? There was plenty of smooth naked back and shoulders for me too ogle too. One of her straps had fallen half way down her shoulder too. Fuck.

She was laughing at herself at how difficult it was to make a coffee in her slightly inebriated state. God I wanted to take her in my arms and kiss her senseless. But of course I didn't.

***

As we sometimes did when I stayed over, we'd decided after showering (separately of course) to watch a movie and crash in the sitting room. The two sofas made an L shape against the walls, so there was me on one, Stacey on the other, our heads close enough that if I wanted to I could have reached out to touch her hair. And I did want to.

So there we were watching a romcom we both liked, Stacey in a long and soft pink Disney t-shirt that went to her thigh and me in pyjama shorts and top. Stacey looked so soft and feminine, her honey coloured damp hair prettily tousled, her breasts large and soft in her nightdress thing. I tried not to notice how high up her T shirt had ridden up her leg and how much thigh was on display. I also tried not to think about her black bra straps, one of which I could see. I imagined the bra was one of those substantial underwired types. Then I wondered if she was wearing panties. Again. Jesus.

At some point we had both stretched our arms out in such a way that our hands were very close to touching.

'Stacey, I-'

She turned to me, smiling. 'What? Spit it out.'

'I just wanted to say thanks for having dinner with me tonight.'

'It wasn't a hardship. It was nice to have a boyfriend for a night.'

Before I knew what was happening, she had linked her fingers with mine. My heart was thumping and we looked at each other for several long moments. Tingles went up my arm from where our hands were joined and my mouth went dry.

'Can I ask you a question?' she said, heat in her gaze.

I nodded.

'Have you ever thought about me as more than your sister in law?'

I took a long breath before I answered.

'Stacey, I don't want to lie to you but I'm afraid of what you'll think of me.'

'I have the same worry. For example, if I said that I've thought about you as more than my brother in law what would you say?'

I swallowed.

'If you did say that, then I'd say that I had thought about you that way too. A lot.'

'But we'd never act on it right? We both love Lorna and would never do anything to hurt her.'

I was both relieved and disappointed. What the hell was wrong with me?

'No, of course not.'

She squeezed my hand then.

'But what if Lorna said she was ok with it? You and me, I mean.'

My cock answered that question irrationally by hardening.

'Well then I'd think she was crazy and trying to trick me somehow.'

'Right.'

This conversation was insane. But god Stacey was so pretty. And those tits. I could see her nipples now through her bra and top. Was she as aroused as I was?

She caught me looking and smiled.

'I should go to bed, Stacey.'

She sighed. 'You should. But what if I told you that Lorna had planned this whole thing tonight, that she knows you want me more than just as a sister in law and that we have her blessing?'

'What?'

'I'm serious. Lorna has watched you trying not to look at me that way for years. Being so careful about it. Sisters talk you know. Here's the thing. She thinks we can be happy together. Being together. You and me. And her. The three of us.'

The image in my mind of the three of us together is something I had fantasised about. What if this could possibly be true? No.

I had an older brother but not a sister, so naturally I very much thought of Stacey as my actual sister and I knew she looked at me as her brother, as it was just her and Lorna.

'It doesn't matter what you say. Unless Lorna turns up on your doorstep and tells me she wants it, and shows me she does, then I'll never believe it. I would never betray her. Or hurt either of you. I love both of you.'

She smiled then as if I had somehow said the right thing.

'Hold that thought. I'll be right back.'

I was 100 percent sober now. What on Earth was going on? I stared sightlessly at the TV as Stacey got up and went in the kitchen, her mobile phone in hand. And yes I did look at her ass, despite everything.

I heard the kettle go on and waited for Stacey to reappear and tell me she had been winding me up the whole time while I told my hard on to go away.

Instead my mobile phone buzzed. It was a message from Lorna.

Shit! I was trying to think how to reply when another message came in.

My heart hammered in my chest.

***

Stacey and I sat at the kitchen table and waited for Lorna. I sipped my coffee.

'You look like you've seen a ghost,' Stacey said

'I can't believe this is happening. I must be dreaming.'

She smirked at me, and leaning over gently pinched my cheek.

'Nah, you're awake.'

Then her hand slid round to my jaw. The contact was electric. We had never touched like this before. I turned into her touch and sighed.

'You're cute when you're nervous.'

I laughed at that.

'You're not nervous?'

'I guess I am a little. And haven't you ever wondered why I get anxious around you?'

Had I been mistaking Stacey's intensity for having a crush on me?

She continued. 'But Lorna and me have been speaking about this for a while so I'm way ahead of you on this. And honestly the way you've been looking at me - or trying not to look at me - for years now, I'm looking forward to getting laid by you.'

My eyes must have gone out on stalks.

Now it was her turn to laugh.

Then I heard the sound of the front door being unlocked and Lorna, not in her nurse's uniform, strode into the kitchen.

***

'He's still in a state of shock I think, Lor.'

We had moved to the sitting room and I was sat between them, my sister in law to my left, and my wife on my right. We had sat like this before but boy, this felt different. The movie was still playing in the background.

Lorna turned to me.

'This is not a trick Adam, I promise. You love me, right?'

'You know I do.'

'And you love Stacey?'

I took a breath. 'Yes. Yes, I do.'

Lorna put her hand on my thigh.

'So shut up and kiss my sister.'

Could I do this? My cock was certainly on board. I turned to Stacey, her pretty face expectant, her lips curved in a smile. My gaze dropped to her chest in that soft pink top and up again. God I wanted to see and then suck on those tits. I might never have the chance again. Fuck it. I leaned towards her, and pressed my lips against hers.

They were soft, warm and welcoming. I had dreamed of doing this but the reality was more incredible. It felt deliciously wrong but oh so right. I kissed her again, chastely, my eyes closed, savouring the moment. My heart was thumping and my cock was throbbing now.

I was kissing my sister in law. The thought made me lose the control I had been trying to hold on to. I deepened the kiss, Stacey returned my kiss harder and opened her mouth, and our tongues met. She tasted of coffee and mint.

'That's better, right?' said Lorna.

I kept kissing Stacey, breathless with a desire that I had tamped down for so long. I cupped her face in my hands as we explored each other's mouths and I sucked on her tongue. She broke the kiss, panting a little.

'Mmm,' said Stacey. 'You were right, sis. He is a good kisser.'

Lorna laughed. 'He's good in other ways too.'

My wife squeezed my hard cock through my pyjama shorts and I gasped. Then Stacey's hand joined hers in my lap and I couldn't help but groan. I had ached to have Stacey's hands there and now it was actually happening. She was more tentative as she felt my hard on through the thin material of my shorts.

'Oh, god, Stacey '

She giggled as she wrapped her fingers around my length.

'Someone's excited,' she breathed. 'You really are my big brother.'

Then Lorna turned my head to hers and took my mouth in a kiss. Her familiar lips were more passionate than usual though. I ran my hands through her ashy blonde hair, much lighter and straighter than her sister's. She was as turned on as I was. My hands fumbled with the buttons of her blouse as our tongues clashed. Stacey meanwhile was wanking me slowly through my pants which suddenly felt a lot tighter.

I spread the sides of Lorna's blouse open and was more than a little happy to see she was wearing her red lacy bra, a favourite of mine.

I started kissing the side of Lorna's neck and worked my way to her shoulder, slipping one bra strap down with one hand while my other felt her breast in its red lacy cup.

Stacey tapped me on the shoulder and I turned. With heat in her eyes, she put her arms up in the air. I hesitated for a moment, a little overwhelmed by what was happening.

'Stacey, are you sure?' I said.

'I'm sure. Come on, you've been wanting to get your hands on my boobs for a long time. Now's your chance.'