When I moved out of my parents' house to study, I eventually found a place with four others -- 3 girls and another guy. We immediately got on very well, and I managed to maintain a coherent conversation with everyone despite my shyness.
The girls were all very attractive, and one in particular I thought was stunning. Slim but with quite large breasts, slender limbs and pale skin. She had thick brown hair that she tied back in a pony tail and when she smiled at me I would melt a little inside.
I started going out at night with my housemates, trying to dance and drinking too much. But I still hadn't had a girlfriend (although I told them that I had lost my virginity years ago). I was way too shy to approach any of the girls for something more serious, and as usual tried to compensate for my lack of communication skills by staying fit and working out.
My addiction to porn continued to develop, and when I wasn't being sociable or working or studying, I spent my free time masturbating and fantasizing about my housemate(s). I felt ashamed about this, but the shame actually became part of my fantasies. The more perverted I felt, the more intense the pleasure as I played with myself.