I am a guy who has a best friend in her late 30s. Once when we were staying at a hotel, we were planning on going out to a night club. I was relaxing in bed watching tv and wearing my pajamas while she was sitting by the desk putting on make up in front of the mirror, with her back towards me. We were talking about this and that and while I observed her I couldn't help feeling a little excited. She has a lovely slim figure, with small perky tits and she was sitting by the desk wearing only a tight top and pajama trousers. She is very pretty too, with short bleached blonde hair and very bright blue eyes and pale skin. Now and then she was turning her face towards the tv and once even a bit more towards me but most of the time she was just doing her make up. So when I was lying there I started fantasising that I could probably risk masturbating right there and then with her in the same room, without her noticing. This fantasy turned me on even more and soon I thought "what the hell - she's too concentrated on her make up". I knew her making up procedure could take quite long, at least half an hour or so. So I decided to risk it. First I was stroking my cock through my pajama trousers, until it was hard. Knowing my pajama trousers were quite easy to slide down without moving my body so much, I slowly did that until they were about halfway down to my knees. Now i was lying there with my cock and balls clearly visible...of course I was worried that she would notice my nudity.. I was lying almost right behind her and We could see each others faces but i was quite sure that my cock wasn't visible to her...she would have to lean to the side in order to see it, or turn her head around a bit. But she was too focused on her making up procedure. So I carefully and slowly started to stroke my cock...by now it was hard as rock. and my heart was beating heavily from the excitement of wanking with her so close. At any moment if she had seen me i would not have time to slide my pants back up. This feeling made me feel extremely aroused and I started having a tingling sensation in my balls. I was careful not to make any sounds, other than talking to her now and then. Besides the tv was on so i was quite safe. The tingling in my balls slowly grew more intense and now i was so turned on that my mouth felt dry...my cock was huge and felt warm in my hand and my strokes were strong and slow, all the way from the tip to the botton of the shaft. At one point she turned her head towards the tv and I got very scared because now I was sure my cock was visible to her, so I froze in my movements, while i was worried to hell she would see me and my throbbing cock. But she was just looking at the tv for a while and then turned back to the mirror. Now my heart was racing fast, and with a slight sigh of relief I continued my wanking, more excited than ever. But then I felt another excitement growing and this was the thought of pushing my risk a bit more...so I lay there masturbating and closed my eyes for a while so I couldn't see her. and I lay like that for a couple of minutes. The thought of her turning again to the tv while I had my eyes closed was sooo exciting...what if she was actually doing that? and what if she happened to see me? or even see me in the mirror. Now and then during this incredibly risky moment, i opened my eyes to check on her and most of the time she was busy with the makeup but a few times she was looking at the tv...and this situation - the whole thing of not knowing if she would turn towards me - made me feel unbelievably turned on. The longer i dared to close my eyes, the more excited i got. On a few occations she said something and i replied, still with my eyes shut. At one point i heard a shuffle and i opened my eyes and saw she had turned her body a bit towards the tv so now she could easily see my cock in the mirror reflection if only she looked at me! Now i was seriously considering the risk too big and thought of stopping but at the same time this dread just turned me on even more. So i closed my eyes again and continued to stroke myself. Lying like that for several minutes with my eyes shut, the tingling sensation in my balls was now slowly spreading up through my cock and i realised i was soon about to come. I intensified my strokes a little, still careful not to make sounds...The tingling sensation spread up from my balls through my rock hard cock. I decided I wanted to look at her while i came so i opened my eyes and saw she was looking at me! she saw me see her and she batted her eyes and giggled. MY GOD! i froze in my movements. the blood in my body was now pumping heavily and all i could hear was my own heart beat - i saw she was saying something but i couldn't hear her! i panicked and couldn't move. my cock was rock hard and throbbing and my hand was holding it by the root, and just then i felt my whole body shivering, and cum was shooting out in several streaks like a fountain... this moment felt like an eternity and all the while she kept her cute eyes locked at mine. when i had finished my orgasm i slowly came to my full senses again and still with my cock hard in my hand she giggled and said jokingly "very subtle my dear friend..." with my mouth still dry, i only managed to say "oops"...i then slid my pajama back on and went to have a shower. we didn't tallk about it afterwards, she only said "you are always so horny" and we left it at that. since then she knows i masturbate thinking about her but she seems fine with it. but this memory remains my best masturbation memory still to this day.