Sister in-law

Yeah I know it is quite "taboo" to even think about having a sexual encounter with the sister of a wife but the pent up fantasy frustration has to come out somewhere... My wife is an attractive blonde, fit and a great mother in her 40s, looking at it from a taboo perspective I have often "released tension" by fantasizing about her sister, tall blonde, active, happy and a little more lively than her sister (my wife) and a few years younger but still over 40.

I woke up this morning thinking about stuff in general as I do... when the fantasy popped into my mind of her sister who was sleeping in the room down the hall as she is visiting while on a business trip. I envision her and I having a nice conversation in the morning. quite alone in the house, sharing ideas and some flirting when I grab the opportunity to hint at something more. 

She responds with a laugh as she does and we continue chatting. I could feel the tension building when we both stand up to grab a coffee in the kitchen I turn to her, grab her hand and pull her toward the bedroom. Here in a fit of passion I kiss her, she backs off, then I grab her and kiss her again on her beautiful lips, down the nape of her neck toward her shoulders while my hands slowly drift down her sides. As I reach the bottom of her top I slowly pull it up exposing her bra that I quickly remove and begin kissing her hardening nipples as I hear her moans of enjoyment. I stop and look at her in the eyes and kiss her again while grabbing her ass, pulling it toward me.

She offers no resistance as I move down to her chest, sucking on her nipples and then on my knees to her stomach kissing her, my tongue trailing down to her panty line that I slowly pull down to expose her gently cropped pubic hair. 

My tongue continues as my hands pull down her panties. I begin kissing her pussy gently as she begins rubbing my head. My tongue penetrates her, she moans as she gets wetter and wetter, her juices flowing out already. I stand up, she grabs my belt and un-buckles it, reaching inside grabbing my cock through my underwear stroking it. I push her down onto the bed kissing her stomach and eating her out as her legs spread wider and wider apart, now she is pulling me in. I then back off and she sits up, pulls out my cock and begins sucking on it. I am ready to cum in seconds and tell her to back off so I don´t lose it. 

She does but I cannot contain myself as I pull down my pants and slowly insert my cock as I look at her face. Her pussy is pulling me in as I begin thrusting. As I thrust she tells me "don´t cum inside me..." and I thrust. I left her legs over my shoulders as I pound away, I am seconds away from cumming... I want nothing more than to cum inside her. She repeats.."don´t cum in me..." My cock is throbbing, I look at her and tell her I am about to cum and where does she want it..."not..." as she pulls me closer and I shoot stream of cum after cum into her pussy. She simply moans in pleasure...

We collapse next to each other wondering what just happened... we know things will never be the same again.