He woke up feeling a little groggy...he always had one too many when his wife was away, but at least he was a good boy this time and was alone in his ...ed. It was 6 am and as he yawned he felt his morning hard on press against his boxers. It was just natural to him to slide his right hand into his pants and cup his balls, they were warm and loose and he gave them a squeeze letting out a soft groan. His hand moved from balls to the base of his shaft and he slid it up to his head where he rolled. Give it to me. Fuck me hard with that beautiful cock of yours,” Lisa screamed out loud.Mark began moving his cock in and out slowly at first and then picking up the pace. He was fucking her asshole in a steady rhythm. He was slamming into her ass with everything he had. He knew that if continued to fuck like this; he was not going to last long at all. Her ass was sucking him back in everytime he pulled out. He continued to fuck her ass until he couldn’t take anymore. He had to unload soon.Lisa. Not just any girl, I had a fixation about with my own sister. Just thinking about what was under her dress was enough to cause a stirring in my groin. Nothing developed at that time except my sexual urges which I didn't know how to handle.I was a naive thirteen year old (nearly fourteen), when I went into the workforce for the first time. I knew nothing about sex. I didn't know that it took a male, be it human or animal, to fuck a female to get her pregnant. I just thought that offspring was. 7” height and well built. I have good length of my manhood which can satisfy any lady. I stay in Bangalore now and was working for a very reputed company while the story happened. Let me tell you this happened around 5 years back and I was taking Guest Lectures in reputed Engineering colleges. We had leave on Saturday and Sunday so I was taking lectures on Saturday while colleges were open.Let me enter into the story. I took lecture on one of the subject and came to back to Bangalore as usual.