This incident happened while I was visiting my big sister in Boston during my spring break three years ago.
While most of my friends were going to Florida for spring break for financial reasons I was stuck with the options of staying home in small town New Hampshire of spending a few days in my sister Becky's apartment just outside of Boston. I decided to go to the big city and I was really looking forward to having some fun with Becky. When I arrived on a Sunday morning I was kind of bummed out to find Becky spent most of her nights at her boyfriend's apartment and I would be living alone in her room for the duration of my stay. Becky had a roommate from Holland whose name was Isabelle, a freshman at a local college. Becky said Isabelle claimed to be bi-sexual and was currently involved in a relationship with an older woman. I also found out Isabelle had invited Chris, a male friend from school to spend his spring break with her. I wasn't a happy camper but I figured Chris had to have been safely gay for this arrangement to have worked. Nothing could have been farther from the truth. I met Isabelle and Chris later that day I found her to be petite, very pretty, though her baby fat was still quite evident. Chris was cute, in a puppy dog sort of way, about 6 feet and probably around 160lbs. It was also obvious he was completely smitten with Isabelle. It was pretty clear she didn't feel a thing for him, poor boy, and at the dinner table both Isabelle and Becky, neither among the nicest people in the world, teased him unmercifully. They finally got him to admit he was a virgin and Isabelle asked point blank whether he would like to eat her out. Chris had a sort of deer in the headlights look and Isabelle laughed at him, saying she would never have sex with someone so inexperienced. I don't know why he didn't leave the apartment then and there but I guess love can transcend any humiliation. By bedtime Isabelle sort of apologized to him and they went off to her bedroom where he would sleep on the floor.
The next morning since the apartment was pretty tiny I clearly heard Isabelle take a shower and leave for work. I had noticed there was a indoor storm window only separated by a curtain between Becky and Isabelle's room. I can't say the thought of having it there pleased me, I was worried someone could peep in on me while I was dressing. Anyway, after Isabelle had left I went to the bathroom to pee and when I got back to my room through a crack in the curtain I could see a pair of bare legs in Isabelle's room. The legs (which were mostly hairless but very nice indeed) seemed to be tensing up then stretching out. Now at 16 I was pure as the driven snow, sad to say, but curiosity got the best of me so pulled the curtain aside slightly for a better peak. What I saw shocked me. Chris was completely naked laying on his back with the crotch of Isabelle's panties between his nose and mouth. I looked further down to see his hand vigourously pull on his stiff, engorged penis. To my virgin eyes his hard-on seemed so large but now I know it was slightly under 6 inches. I was horrified but enraptured and I found myself wishing I could lick the tip of his cute pink helmet. Suddenly, he lifted his bottom and I saw the helmet literally explode. Several thick spurts of white semen shot out of his sprit hole into the air, one after another. Much of it was landing on his chest and tummy, my word I never knew sex could be so messy. He continued to milk his penis until all the liquid had oozed out and it was plenty. Exhausted, he set Isabelle's panties aside and the last glimpse I got, before I pulled the drapes to, was the lovely contrast of the fresh white semen against his dark, nicely cropped pubic hair. I thought I might have been caught when he stepped into the hall but he was just going to the bathroom. Nevertheless, I thought it best to feign sleep for awhile while Chris took a shower. He returned to Isabelle's room, and, again curiosity got the best of me so I peeked inside. Chris was still naked, the semen stained pubic hair was now clean and jet black. He seemed to be looking for his clothes but then he picked up Isabelle's panties and put the crotch under his nose for another deep sniff. I literally saw his penis bob to life again and he laid down and began to play with himself again. It was so beautiful I began to rub my dampening bud but only over my panties, such a prude was I. Within a couple minutes Chris was spurting again and I was beginning to have my own climax. At first my climax seemed pretty minor and partly through shame I crossed my legs. It was then I was hit with a staggering wave of sheer bliss, so much that I had to bite my arm to stifle a cry. Once the tremors subsided, I managed to drag myself back onto my sister's futon and fall asleep. I woke up an hour later. I noticed Chris was gone, so I stripped down for a shower. My panties were still moist and practically stuck to my crotch. The prude in me was grossed out but the new found devil that had possessed my soul let me drop them in plain sight for everyone in the house to see near the clothes hamper. I felt so dirty leaving them there but I was hoping I also had the power to turn on a certain someone with the cutest pink helmet.