Just discovered this thread!!
It reminds me of a similar situation with a woman I once lived with. My mate really fancied her and they did get on very well. I often fantasised about her and another guy, and in discussion with my mate one time, he let slip just how much he liked her.. I dared him to see how far he would get as I was convinced that she wouldn't go for it.
Well, almost six months later, after much flirting on his part, and outings and visits with the three (sometimes four, with his g/f) of us, he got her in a situation whereby she was a little drunk after a party at the house, and they indulged in some heavy petting. I didn't see this, but he did feel he had to tell me what went on before I found out some other way...
Apparently he had started kissing her as they danced and she responded, they went outside and continued with the exploration of each other. I was hugely turned on at this and asked for details, but my mate was a bit shy telling me this, but he did manage to feel her pussy through her
knickers and suck on her nipples...
I organised a situation whereby she would be alone with him by pretending that my work was delayed, and I would turn up later. I called when I knew he would be there, so she wouldnt call him and say not to come over.
It took him about an hour of chatting, flirting, touching, to start the petting again, and to get her out of her clothes, ...he said she was very nervous, but her pussy was very wet as he managed to get his fingers in there and finger her to orgasm. About a hour before I turned up, he f*cked her and finished her off from behind over the back of the sofa.. It took him ages to tell me this, but I knew what had happened when I turned up as the atmosphere was a bit tense. She was keen to have sex with me after he left and we went to bed and I f*cked her long into the night in what was one of the best session we ever had. Our sex has been enhanced by this and she still secretly sees my mate on occasion, although I doubt she knows what I know!!