Her Sister. I was lying bout the house one afternoon feeling kinda sorry for myself, the GF had just stormed off to the shops after we had a row over me forgetting to put the bins out or something, I was just flicking through the channels when I heard a text come on my phone, Looking at it I didnt recognize the number. 'Hiya, I hear síles thrown one of her hissy fits again, want some company?' I was bemused..'who the hell?' picking up the phone again I text back 'who is this, dont know the number' after a few more minutes the phone beeped once more looking at the screen I seen a image had been sent. Opening it I read..guess who..scrolling down the pic I was shocked then turned on seeing it was Grace, Síle's 20 year old sister..her blouse open and her pert little boobs on display her right hand pinching a delicious pink nipple..scrolling down I could see her other hand buried in her white little panties. 'Holy fuck I thought' Must be a day dreaming....I replied.. sure come over, Not sure what the picture is about lol' trying to nonchalantly play down the pic in case it was some bizarre honey-trap or something..Síle could be a devious bitch when she wanted to be, but surely she wouldnt get her sister in on it. 2 hours had passed and I had almost forgotten about my mystery texter, then just as I was about to sit back in the couch the doorbell went.. heading to the door, I could see the small frame of Grace through the frosted glass window. 'Hi Mr' was the first thing I heard when I swung open the door, Grace standing with her hairs in pigtails and a tight little white top and hipster jeans clinging to her perfect frame, the white top didnt quiet cover her tummy and her toned sexy mid-drift was in full view. 'O Hiya, I thought you had been winding me up, what the hells the craic with the picture!! your sister will kill us ya eejit, what are you playing at?'.. she bit her bottom lip and asked can I at least come in?' I nodded and checking up and down the road careful looked a second time just in case as she squeezed in the door past me, her light perfume shooting up my nose and making me hard...'Oh fuck I thought' In the living room she sat on the couch patting the seat beside her with a devilish grin ' so come on sit down and tell me whats happened' a bit unsure I eased myself into the big chair, making sure to keep a respectable distance from the nubile young lady beside me. '...ah I can't figure that sister of yours out at all....what am I doing wrong?...... I had been telling Grace the story for about 2 minutes and was getting it near impossible to concentrate on my conversation as she was running her hand slowly along her thing as the other played with her hair 'is she flirting with me?' She just nodded and smiled in response to my speech, I was starting to think is she even listening?. Then withouth warning she lunged at me...I backed up 'whoooah...what you doing?..are you mad?... jeez Grace I am 10 years older than you and dating your sister ...er hello?' she just gripped my collar and said.....'so your not going to tell her I was here, sucking your cock and getting fucked by you ?..I was speechless....' what do you mean..but we arent? I think this is a bad Idea' though my inner horn dog was starting to try and sway my judgment, at the same time I felt her small hand tugging at my fly... if I was in my right mind I would have objected..but come on lads, I mean what guy wouldn't be flattered by a lithe young sex kitten massaging your ego with such a display of desire for you!!....I let her continue, and she smiled wickedly as she fished out my cock which was hard since she walked in the house, 'hmm what have we here she giggled...looks like sister kept quiet about this one' I groaned as her little fingers gripped my cock at the base and started to slowly jerk me.....'who the fuck though her this?' was first though through my mind..the second was something along the lines of '''hmmm fuck thats nice...oh sweet jesus' as I looked and she had devoured the head of my cock with her pretty pink little lips.. I stretched my legs out My hand involuntarily reaching for her head as I caressed her head and encouraged her to inhale more of my cock, her murmurs were of satisfaction.. my balls were tingling as I felt the back of her throat open to take the head of my cock deeper....'holy fuck grace' I uttered...her sister certainly didnt deep throat and here was her supposedly innocent sibling swallowing me to the root!!...suddenly she pulled away from my cock and leant into me kissing me deeply, her soft lips hungrily fighting mine...between breathy kisses she said' Please fuck my throat..I'm on my period and I so need some sort of release...you dont mind do you.. you know I've always had a crush on you' her barely audible words made my cock throb...'sweet jesus grace, you cant tell anyone about this' smiling devilishly she said' I know..our little secret..I know shes not been giving you ny lately, I heard the silly cow telling her friend on the phone one night, I wouldnt deprive you u like that Dave' with a smile and another bite of that bottom lip she dived her mouth back on my cock and started to suck me slowly, her innocent blue eyes looking into mine as she willed my cum into her mouth. At 5'2 she was petite yet perfectly formed, 32 b breasts dark blond hair and full luscious lips, this girl was made for sinning, and god help the guys when she reaches her sexual peak!!!....Back to the sofa....as she slowly managed to swallow my 8 inches she started to gaga a bit.. I asked ' you ok..sure you can handle it?' she just winked and started to force my hand to the back of her head, encouraging me to push her head down more.. at this stage my ass was starting to buck at her face, I hadnt even removed my pants, looking across her tight young body I couldn't help but notice her ass and hips gyrating against the arm rest of the couch. 'Hmm fuck ...good girl Grace swallow that cock.....your a naughty girl aint ya? here sucking your sisters fella...your a little slut !!!!..arent you' I repeated emphasizing my point with a light smack to her jean covered ass she just looked at me and groaned ..the vibrations of her throat pushing me closer to cumming. I was afraid I'd cum too soon, I was really enjoying this, and I had to admit I was getting off as much on being a selfish bastard letting her do all the work ( which she obviously was enjoying) as I was on the sensation and the fact she was my Girls younger sister. I looked into her eyes my mouth open..unable to string a sentence together.. bar the odd utterance of 'good slut'..or 'hmm fuck your a talented little thing arent you' the sensations were so over powering, I grabbed her pig tails and started to buck my cock into her mouth her nose was against my pubic hair, her moans getting loader and in turn the vibrations in her throat pushing me to the edge....'fucking hell...how do I get myself in these situation' I thought. Just when I thought it couldn't get any more intense I felt it, not sure at first but fuck..she had got her tongue you to flick across the underside of my balls, despite the fact my cock was lodged in her wet warm sucking throat..'oh fuck grace.. slow down..please stop.... she tried to smile despite my cock having her lips spread obscenely My body started to betray me, I grabbed her head with both hands and roaring like a bull started to buck into her mouth.. My thick hot cum shooting in her throat, the reflex action of needing to grab something as I came holding her head from moving.. her throat started to spasm then I realized she was trying to swallow me...'Oh god Oh holy fuccccccccck!!!' Letting go her head I slumped back on the couch, my breath driven from my lungs, looking at Grace she was wiping a stray drop of cum from her chin and playing the drop on the tip of her delicate finger against her tongue. 'Hmm you taste yummy.... I needed that hun' getting up from the couch I could see the damp spot in the crotch of her jeans, she licked her lips and leaned into me, kissed my forehead . 'next time lover I might need you to fuck me... now try and look respectable, Grace is over at the house with Mam and she'll be back soon, I knew she'd be a while so I took my chance, I needed a nice cum snack' she said with an impish smile. as I lay breathless on the couch I tried to process what exactly had happened in the last 20 minutes. The closing of the front door stirring me from my trance.