Not an Easy Decision

My wife and I often masturbate together as a pleasing alternative to intercourse. It thrills us both to display ourselves to each other and to watch each other reaching a hot climax. And it is also a wonderful experience when our timing is perfect and my spurting cum acts as a trigger for her own sexual release. During the build-up to our respective climaxes we urge each other on in the most unashamed way and it is fortunate that we do not have close neighbors to overhear us.

Recently my wife's younger sister came to stay for a long weekend and over those few days we were careful to conduct ourselves more quietly. However, when I got up one night to take a pee I heard my sister-in-law gasping quite loudly as I passed her bedroom door. At first I thought she had been taken ill but it quickly dawned on me that she was masturbating and was close to reaching her climax. On realising this I was filled with sexual excitement and my cock began to stiffen. So, standing there in the hallway, I began to stroke myself, enjoying every sexy sound and trying to imagine how she was playing with her clit and wet teenage cunt. Soon she was coming loudly and within a second or two I was pumping my cream into the cupped palm of my other hand. I cleaned up in the bathroom and listened again at her door on my way back but there was no sound and I guessed she had drifted off to sleep.

A night or so later, after my sister-in-law had returned hone, my wife and I were enjoying another masturbation session together. While I was kneeling between her thighs watching her fingering her clit I casually asked her what she would do if her sister happened to walk in on us. Instead of her answering in a lighthearted way as I expected her to do, she arched her body up and pushed two fingers deep into her vagina and said hotly that she would get her to suck me off. Then she related in some detail how she and her sister used to masturbate together before we were married. I then divulged how I had heard Sis making herself cum one night and how I had jerked off listening to her.

This confession brought my wife to orgasm straight away and she cried out loudly as she came. At the same time I knelt up and shot my cream all over her belly and tits. Nowadays my wife and I fantasize about her sister a lot and we are in two minds whether to ask her back for the very purpose of inviting her join in our sex play. It has obvious appeal but it not an easy decision to make. Although my wife is sure that her young sister would be willing I cannot help wondering if we would be going too far. If any readers would like to comment we'd be glad to hear.