First Time Masturbating for my Sister-in-Law

This is a 100% true story.

My sister-in-law is 10 years younger than my wife, but looks very, very similar. They are both quite short, but fairly big girls, with enormous tits and lovely big bottoms. Just how I like my ladies!!

I've always flirted with my sister-in-law and she has always been the same. She has known for years that I have a real fetish for sexy knickers, and used to take enjoyment from wearing jeans that when she sat down or bent over would expose the top of her knickers or indeed the thong she was wearing. She knew full well it was a huge turn on for me.

One weekend she was at my house and I'd been working in the garden all day. I came in to find her sat on the couch with my wife opposite. We live in a bungalow so from where my sister-in-law was sitting she could see right into my bedroom. As I entered the room, my sister-in-law bent over and picked up a cup of tea off the floor exposing a gorgeous red satin thong. I felt my cock twitch immediately at the sight. She immediately looked straight at me and smiled. She knew exactly what she had done. I told them both I needed a shower and walked to the bedroom.

Now I've always been comfortable with my body and don't mind exposing myself when the time and place is right. I left the bedroom door partially open and stripped down to my boxers. I made a point of walking past the partially open door a number of times, stopping for a second each time. Every time I did, my sister-in-law looked at me. My heart was beating so hard and fast and my cock was quickly getting hard.

I took a shower, all the time stroking my cock thinking about my sister-in-law. Once out, I wrapped my lower body in a towel and left the bathroom. My sister-in-law was still sat in the chair and immediately looked across at me. Seeing me just in the towel made her smile.

I suddenly thought, what the hell, and dropped the towel to expose my now fully erect cock. My sister-in-law's eyes stared at me, just occasionally checking to make sure my wife didn't notice as she was still sat opposite her in the same room. I walked to the door, took my cock in my hand and slowly masturbated in front of her. She watched intently as I slowly pulled back and forth. I knew I was going to cum quickly, so dragged the towel with my foot towards me, and then shot several jets of hot cum all over it. My sister-in-law smiled at me again, as I quickly cleared the towel and got dressed. It was the most exciting thing I had ever done, and led to several more encounters with my sister-in-law. 

She admitted to me much later that as soon as I had finished my show, she excused herself, went to the toilet and masturbated. She said her pussy was so wet and she came in seconds.