Slut Sister-in-Law

My wife is a flirt but compared to her sister, she’s a nun. Carol is a real raver. She’s in her early thirties, curvy with big boobs and long legs, long black hair and sexy smile. She’s divorced but did well out of the settlement having her own house, car and spare cash. So, she treats herself well. Alison, my wife, loves her dearly but has to act as the big sister to try and keep her in check. When they went out recently on a hen night, Alison returned at two in the morning and told me that she’d left Carol with the two guys that had chatted them both up in a club. When I pressed her as to whether she’d ‘done’ anything she went coy but I trust her. Carol on the other hand is a real slut. I heard later that the two guys left the next day after having Carol in a threesome, then in the shower, and finally they were only allowed to leave after both had given her a good spanking ! I smile when Alison tells me the stories but secretly wish she might take a leaf out of her sister’s book on occasion.

The incident I’m writing to you about took place when Alison was out of town for the week on a training course. I stayed late at work one night and went for a drink after – it was around 8 o’clock. What I saw as I entered the bar nearly made my eyes pop out. Carol was seated on a high stool at the bar, she didn’t see me but I definitely saw her ! She was wearing the shortest and tightest skirt imaginable. Her long legs were in black nylon with spiky black heels at the end. She had on a low-cut stretch top that was barely keeping her tits in place. She was well made up and flirting with two guys at the bar. I watched from a distance as the guys got bolder and started to touch her legs and arms. Carol smiled and after a short while they all left. I followed at a discrete distance and watched them get into a car, Carol and one of the men in the back. I tailed them down a country lane as dusk fell. The car pulled off the road into a dirt track and stopped. I hid my car and carefully walked towards them. I could hear Carol giggling as I got closer. My first glimpse confirmed everything I though about Carol. She was on all-fours on the back seat. Both doors were open and she was being fucked from behind whilst she was sucking-off the other guy as he stood in front of her. I watched for a while but the guy fucking her couldn’t last and he grunted as he came, filling her with spunk. From my viewpoint I could see it running down the back of her thighs. This set off the guy in her mouth and he doubled over forwards before almost shouting ‘OH Shit…’ and came in her willing mouth. He pulled away and Carol climbed out of the car. I pulled back and walked back to the car, expecting them to leave soon. After a few minutes, I heard raised voices and then Carol arguing with one of the guys. I got back out of the car, grabbing the tyre lever as I did so. I crept back as Carol’s voice became muffled and I heard the car start. I was about to leap out to defend her as a male voice said, “Don’t worry love, we’ll be back with some friends later” and the car sped away. I cautiously and quietly crept around the corner, looking for Carol. I couldn’t see her so I walked further. Then I spotted her. Carol was tied to a tree. She was facing it with her arms wrapped around its’ trunk and her ankles spread open by a branch and then tied also. She was completely naked. It was all I could do to not laugh out loud. My sister-in-law, slut of the nation, being held for sex. The guys would return ‘with friends’. I smirked to myself at the thought, and also developed an erection at the combination of the thought and Carol’s lovely body in front of me, spunk matted to her thighs. “Who’s there ?” she spoke as she heard my steps. She craned her neck to see but she was too close to the tree to see properly. I moved quickly to stand close behind her, directly behind her so that she couldn’t identify me. I considered what to do. “Please,” she began, “let me free”. I couldn’t speak as she’d recognise my voice. “Pleeeaassssse” she implored. I said “Mmm, o.k.” in the worst mock-scottish accent you could imagine. It was all I could do to stop from laughing. I looked at her for a while longer and couldn’t resist reaching out and stroking her bum a little. She gasped slightly and then relaxed. “Please untie me,” she started, “I’ll make it worth your while…”. I pondered this but couldn’t resist stroking her smooth arse once more and letting my fingers wander towards the crack. “I’ll let you do whatever you want” she continued. I smiled to myself again. Keeping up the same accent I said “You look good like that, it seems a shame not to slip you a length myself”. “ She giggled and said, “If you let me go, I’ll let you tie me up again later…when we’re alone and more comfortable”. Alison had said that Carol had mentioned bondage to her before. “Promise ?” I quizzed. “I promise” she returned. I told her to wait and I returned to the car to get a knife and my long coat. I carefully removed the branch from between her legs and her weight sank back onto lovely thighs and calfs. I draped the coat over her shoulders and quickly skipped around the tree to untie her wrists, being careful not to be seen just yet. Her arms flopped down and she rubbed her wrists. She whispered ‘Thanks..’ and walked around the tree. Her face was a picture when she saw me smirking at her. Her expression changed to that of mock anger and she raised her fists to bang me on the chest. As she did so, my coat slid off leaving her naked once more. I held her wrists gently as her face changed again to one of embarrassment. I spoke “What say we get out of here before your ‘friends’ return ?”. We grabbed her clothes and bag and as we drove back I told her about seeing her in the bar, following them out to the country, watching the guys come inside of her (she blushed scarlet as I said this) and then getting suspicious and finally finding her. She fell silent. I told her I thought of leaving her to the mercy of the returning group (how many I wondered…). She blushed again. We drove in silence until we arrived back at her house. She started to explain how she got lonely etc… but I told her not to bother and what she got up to was her own affair. She kissed me on the cheek as she left the car but I threw in at the last minute “So, when do you keep your promise ?”. I gave her a broad smile but she didn’t seem to see the joke. I drove off and when I got home, pulled out some photos of Carol from the drawer. I wanked over them.

…oooOOOooo…

Carol phoned the next morning and apologised for everything. I told her not to bother and I wouldn’t tell Alison. It would be our secret. She thanked me and invited me over the following night for a meal. I told her not to bother but she said she owed it to me and Alison had asked her to keep an eye on me whilst she was away. I laughed at this and I could feel her smiling in return. We said goodbye.

After work on Wednesday I went home to change and arrived at Carol’s at around 7.30pm. There was a small note on the door ‘Paul, let yourself in’. I tried the handle and the door opened. I walked into the hall and stood waiting for a sign. Carol’s voice called me upstairs saying ‘Could you give me a hand please’. I pushed open the bedroom door. Carol was spread-eagled on the bed. She was dressed in a white bodice, white stockings and heels. Her tits were pushed out over the top of the bodice. She was face up with her ankles wide apart. She had cuffs on her ankles and these were tied to corners of the bedstead. Her left wrist was handcuffed to the bed-head but her right arm was lying by her side. “Well,” she began, “I can’t do it all myself” and waved her arm in towards the bed-head. My cock leapt immediately and I needed no further prompting. I picked up the spare handcuffs and secured her to the bed. She looked up at me slyly and just said “A promise is a promise”….