drawing me masturbate

I work as a model for artists mainly nude. The drawing sessions are usually organised by art groups or galleys. We get a large variety of people attending male, and female all ages from 17 to 70. I never usually do private sessions but on one occasion i was asked by a lady in hermid fortys if i woul pose for her in her workshop at home, i agreed because the money was good. When i arrived she had placed just a large bean bag on the floor and asked if i could lie on it with mylegs together stretched out with i slight bend in my knees. This was ideal for me because i can just relax and think about other things and not worry about holding a hard pose for ages. After about two hours of drawing, breaks then more drawing she started saying how she loved drawing the male body and would love to draw a guy with an erection. She diddnt hae to ask me twice, i slowely stroked myself to a full firm erection, while kneeling on the bean bag with my hardon pointing at her i could see how delighted she was and she could tell i was horny because my cock was twitching like mad. "how about i get some baby oil out" she asked " and you can sroke that lovely hardon for me as i paint. She dsapered into her house and came back with a bottle of lotion and rubbed it into my cockrubing it all over my shaft and balls " wow i love that its so firm, and the effect of the lotion on my cock and the light is awsome" she said smileing at me. The next hour a spent kneeling infront of a 40 year old woman strokeing my lubed up cock applying more and more lotion and pulling the skin backso she ould se my head. I shot one hell ov a load of cum all over her wooden floor. She thanked me and asked ifi wanted to see the finished art and i said yes. The finished work was fantastic she had drawn me in many diffrent states of arousal and me ejaculating at the end all on one large canvas. " That was fantastic "she said " thanks for shareing that with me and for letting me draw it" She paid me a å£20 bonus and i had one of the best wanks ive had for ages. I wounder how much my picture will be worth if she becomes famous.