This story is 98% true and accurate. Its changed slightly because this  happened 4 years ago in late January/early February of 2003 and my memory is a  little rusty, but this is as true as I can get it.
          
          First, a little  backstory: I had been working at a high school in a neighboring suburb as the  evening supervisor for about 6 months. Things were going smoothly. My  'girlfriend' of about 3 years had moved with her family clear across town about  a year before with only 1 visit at around the time I had started the new job.  So by this time it had been awhile since I'd enjoyed the company of a woman. 
          
              A fairly attractive  woman on my crew, who I will refer to as "V", had started becoming  more and more friendly with me over the past few weeks, and I could see that  things would become very interesting if   I stayed with it. She was a 27 year old, 5 foot, 100 lbs, hispanic  beauty that had taken a liking to me ever since she and her live-in boyfriend  were on the verge of a split-up. V was a bit of a tease; my trips to check on  her usually ended with some making out and heavy petting. But she always  stopped when things starting getting interesting. And my limited spanish and  her limited english only served to increase my frustration. I took every  oportunity to flip through a spanish-english dictionary I had borrowed from 1  of the classrooms, hoping that I could build upon what I remembered from my  high school spanish. With my limited vocabulary, V said that she did love me  and wanted to be with me, but wanted our 1st time to be special. Fortunately,  another crew member, "J", was friends with V and helped our fledgling  relationship by being our translater. 
          
              By being our  translater, J quickly picked up on the state of the relationship between V and  I, and apparently decided to take advantage of the situation. J wasn't as  attractive as V was (she was a little on the thick side), but when she started  to lightly flirt with me 1 day, I didn't exactly turn her away. I didn't  exactly encourage her to continue, but I didn't discourage the behavior either.  Anyway this continued for awhile behind V's back until J started to make it  more and more clear she was interested in me.
          
              "I need a vacuum  cleaner," she told me 1 day. We used those commercial backpack types at  the school that were seemingly always breaking, so working spares were kinda  hard to find. Unhappy with the realization that we were gonna have to search  every janitor's closet in the sprawling school, I grabbed my keys and we  started the trip making idle chit-chat. Fortuanately, I found a spare pretty  quickly, but it lacked the metal tube and floor attachment that made up the  business end of the vacuum.
          
              "Cool," I  said, "the tube should be easy enough to find; theres an extra in almost  every closet."
              "Well I don't  want 1 thats all messed up, I want a good one." she said.
              "I'm sure they'll  all work about the same."
              "No...some tubes  better than others," J said with a barely visible smirk. Catching the  inuendo, I decided to play along as we made our way to the next closet.
              "Oh? And do you  know this from experience?"
              "Maybe..."  she said.
              We arrived at the next  janitor's closet and started looking for the attachment. A minute of searching  yielded nothing, so I asked her, "Find it?"
              J glanced up at me and  said, "No."
              I turned back to the  rack of various cleaning chemicals for 1 last quick look, hoping I had  overlooked it when I heard her mutter, "I really need a long tube for this  thing."
              Unable to resist, I  said, "Yeah, you'll be thinking 'long tube' after I get through with  you." She didn't respond, only looked at me with an expression that seemed  to say, "Oh yeah?" 
              After several moments,  J finally said, "Well?"
              "Well what?"
              "Well make me  think 'long tube'" she said boldly with an amused smile.
              I said nothing, made a  vaguely dismissive sound and started heading towards the next closet. After a  few moments, I heard her close the door and ran a few steps to catch up with  me.
              "Aren't you gonna  make me think 'long tube'?" she asked. 
              "Hmmm..." I  said, acting like I was thinking about it, "Maybe later when I have  absolutely nothing better to do."
              She smiled to herself  and stayed quiet until we reached the next closet.
              "Show me,"  she said as I searched the small room.
              "What?" 
              "Just whip it  out," she said with a mischeivous grin.
              I hesitated a second,  "I can't do that," I said nervously. 
              "Just do  it."
          
              I spotted the  attachment in the corner and pointed to it as I semi-quickly left and returned  to the storage room/break room that also served as my office. I sat down and  replayed events over in my head, mulling the possibilities. Did V ask J to do  that to test me? Or was J looking out for her friend and testing me secretly?  Or was J actually interested in me?
          
              I really didn't want  to screw things up with V. Especially over something as stupid as a 1 time  fling with J. I thought it over a second: that HAD to have been a test set up  by V. Had to be. Friends don't play matchmaker and then swoop in to wreck the  budding relationship...or do they?
          
              Lunch break rolled  around (actually on evening shift its dinner break) and after everone had  eaten, the crew broke up into small pockets of conversation to kill the last  few remaining minutes of break time. V and J, as usual, drifted over to my  table and, with J acting as translator (and as though nothing had happened  earlier), V and I exchanged the usual pleasentries for a few minutes before she  gathered her things, quickly kissed me, and left to finish her work for the  evening. J flashed me a quick grin behind V's back and left to finish her work  for the evening as well.
          
              And that was how  things went for the next week or so: I would check on V, make out and leave  frustrated with a raging hard-on, only to check on J and have to endure her  flirting which was becoming more and more direct. And after work I would go  home and jerk off to get some relief.   Things changed one day:
          
              I had checked in on V,  which quickly escalated into a furious dry-humping session that ended when I  realized that she just wasn't going to give in that day. I left with the usual  boner of steel and headed over to check on J. By this time my erection had gone  gone a little as I found her cleaning cart half-hidden around a corner. I  looked through the little windows in the classroom doors nearby and found her.
          
              "Everything going  ok so far?" I asked.
              "Yep," she  said.
              I glanced around the  classroom and turned to leave when she said, "Would you get me another  roll of paper towels off my cart?" She seemed to have plenty on the roll  she had in her hand, but I caved in and retrieved the roll for her. 
              "Thanks,"  she said as I set it on a desk next to her, "Want to do something else for  me?" she asked in her best 'fuck-me-now' voice. 
              Sensing another  rejection, she dropped the pretense and turned serious, not giving me a chance  to speak. "I won't tell V. I know you want to be with her and thats fine.  I'm not trying to steal you," she smirked, "I just want to have some  fun. Girls like to fuck too."
              I decided to see where  this could go. "So you'd be perfectly happy fucking just once and will  never tell V?"
              "I'm not some  evil bitch," she said turning serious again, "Well, I can be a bitch  sometimes." Her expression then turned wicked and lowered her voice,  "I really want to fuck you before she does."
              I sat at a desk and thought  about it for a second. "Why the competition?" I asked.
              "I'm not  competing," she said, "You and V can be together after I'm done with  you."
              I hesitated a long  moment, I felt my cock stiffen at the thought of what could happen, "And  you promise you won't tell anyone?"
              "I told you I  wouldn't."
              I sat there  thinking...torn by indecision. I was so tempted...
          
              "V isn't going to  do anything for a long time." J said, "She's a bitch like that. She  even treats her boyfriend like that. But they hate each other so I don't know  why they stay together." She let that statement hang in the air, but I  tried to ignore it. "You know what you should do?" she asked in a  teasing voice, "You should totally teach her a lesson and get her  back." She grinned widely, "And I know how"
          
              I was horny and wasn't  really thinking straight. I wanted to say 'yes', but I was held back by the  thought of V. "Now?" I asked. I don't really know why I asked that. I  was just trying to get more info to make a desicion, but J took it as my answer.
          
              "Not here. Goto  the next hall over where they're doing that expansion. In the new maintenance  garage theres a ladder leading to a loft thing. I'll meet you there in 5  minutes. I have to hide my cleaning cart."
          
              I stood and followed  her out of the classroom, watching her scurry over to her cart. I headed over  to the construction area, where the new expansion was coming along. I made my  way to the future maintenence shop/garage and spotted the ladder J had mentioned.  I headed up and looked around. Only a few lights were mounted and even fewer  were wired up. Naturally, none were on. On one side of the 'loft' area was a  door. I opened it and saw that it was an electrical room: there were a few  commercial circuit breakers, some telephone and LAN lines beside a few TV-sized  transformers. 
          
              I waited for a minute  or 2 before I started to get cold feet and think about what I was doing. In a  brief moment of sanity I decided to leave. I decended the ladder and left the  garage, as I opened the door to the hall I saw J duck into a doorway  momentarily before dashing the remaining distance to where I stood. 
          
              "What are you  doing?" she whispered as she pushed me back into the shop. 
              "I..." I  trailed off as she ushered me back to the ladder.
              "We don't have a  lot of time. Come on." She moved to the ladder and started up first. I  remained transfixed for a moment on her hips as she climbed up. Her thick (not  fat) ass undulating seductively under her pants as she climbed. And between those  legs... was what I desired. She was here for the sole purpose of giving me what  I wanted.
          
              My lust renewed, I  followed her up the ladder. She looked around the loft for a moment before I  made my way to the electrical room to the side. She followed, saw the room and  said, "This'll work." before closing the door behind us. I'd turned on  a worklight that a worker had left behind. 
          
              J spotted a good sized  spool of wire on its side. About a foot tall, she made up her mind, "Take  off your pants and sit down." I loosened my belt, unzipped, let my pants  fall and pulled down my underwear. By the time I was sitting on the spool, she  had pulled her pants and underwear off of 1 leg and positioned herself over my  lap. Grasping my hard cock, she lowered herself until my cock head was just  inside her vaginal lips. 
          
              Rubbing it up and down  the length of her pussy a few times, she said, "Don't cum in me." And  then sank all the way down on my cock. 
              "What?" I  asked incredulously.
              She had already  started rocking and bouncing on my cock. "Don't cum in me," she repeated  with a surreal mix of breathlessness and off-handedness. "Unless you want  a souveniour," she said with a dazed smile as she moved a cupped hand in  front of her lower abdomen, as if rubbing a very pregnant belly. 
              "What about  protection?" I asked, trying to ignore the gripping wet heat that I was  buried in.
              "It's fine,"  she breathed, "Just don't cum in me." She said it so blithely and  flippantly that I was convinced that she really didn't care.
              "And what about  when I'm ready to cum?"
              "Just tell me  first, I'll move."
          
              As J continued to  bounce on my cock, I fought to gain control of myself, knowing that this could  turn disastrous at a moment's notice. I'd foolishly assumed that she had  protection or was on the pill. 
          
              I knew I had to stop  this, but it just felt so good to have a receptive pussy wrapped around my  manhood. Oh how I wanted to give in and just blow inside her without worry or  consequence, but I knew that giving in to that urge could get me a 'souviniour'  and forever cost me my future with V.
          
              I knew that I had to  stop this now. I grabbed her hips and tried to stop her erotic movements on my  cock, which by now was on a dangerous hair trigger. "Let me finish up  doggy style."
          
              She tried to ignore me  and keep going, but I held her hips firm. "I want doggy style now." I  said firmly. After a long second she got up and we traded positions, she bent  over the spool and braced herself on it and presented her ass to me. I knew I  should go now, but the urge to cum over-rided reason and I found myself  slipping back inside her. 'I'll pull out,' I told myself, 'It'll be fine.' 
          
              I pushed in all the  way and started thrusting with all I had. I felt my orgasm rush up in seconds.  As I yanked my spasming cock out of her hole, I felt the first stream spray out  a fraction of a second too early, inside J's unprotected body. The second, third,  and remaining spurts splattered her thigh, ass, and floor. 
          
              "What the  fuck?" she seemed very agitated at the mess I had made on her. 
          
              "What?" I  asked as she tried to wipe my semen off her ass and thigh with her hands.
          
              "Dammit" she  muttered. She gave up on trying to clean herself up and plopped down on the  spool, looking unhappy. 
          
              Without a word, I  pulled up my pants and left her there. The whole event lasted maybe 3 or 4  minutes from penetration to ejaculation, but I wasn't too concerned. After all,  J got what she wanted. After that J became quite uninterested in me and acted  as though nothing had happened, even in private. She never indicated one way or  the other if she ever noticed that 1st accidental stray blast inside her.
                      Fast forward maybe a  week and a half, and through a combination of spending extra time with V,  learning a few more words of spanish, and making sure she saw the condoms I  carried in my wallet, V and I consumated our relationship and fucked for the  first time in an algebra classroom (with a condom, unfortunately). I got her at  least once a day almost every workday for maybe 2 more weeks until I decided to  make our union a little more permanent.
          
              I went to check on V  and get a little action like usual and everything was flowing as well as her  juices. We were both naked on the floor, I was on top of her groping her tits,  my hardon in her little fist as she rubbed my cockhead on her clit and lips.  After a few minutes, she was plenty wet and told me to put on a condom. Knowing  that she and I were meant to be together, I released her tit, took my cock to  her entrance, and looking into her slightly confused eyes, I pushed into her  bare. She gasped, stunned for a moment before telling me to use a condom. She  plead a little and weakly tried to get me off, but I ignored her protests and  kept up the rhythm. After 10-15 minutes, I stopped and pulled out almost all  the wayout of her pussy, leaving only the head between her lips, and stayed  there. She looked up at me and understood that I was giving her the choice.  Without a word, she grabbed my ass and pulled me back into her. Knowing that  she had made the decision, I continued for a few more minutes before I decided  that I had to get back to work and blew my seed deep inside her womb.
          
              The next day was  almost the same: told me to use a condom, I refused at first and fucked her for  awhile before offering the choice, which she always chose bare. After only a  few more days, the boss called a meeting and said that our company had lost the  bid for contract renewal with the school district. I immediately took advantage  of my saved up vacation and sick days and used them before we all lost our  jobs.
          
              I  asked V to move in with me, but she refused.  I called her occasionally and eventually learned she was pregnant. I wasn't  about to leave my child behind, so I pursued her more aggressively, even one  time telling her that I would go to court to get my child if she didn't agree  to move in with me. She left her boyfriend after a few more months and  disappeared with her family's help.
                      Fast forward 2 years  and V contacts me, saying she wants to be together again. I tell her only if I  get to be a father for my child. She hesitantly agrees and I ask for such  important information such as what is my child's name, my child's birthday, my  child's gender. She breaks down and tells me that her daughter, "C",  was born in early September, almost 60 days ahead of my estimate. Knowing that  a child concieved in early February should have been due in early November, I  already know what she will say next: C isn't my child. 
          
              Putting that aside we  move in together and make the best of the situation until V happens to mention  that she and J still occasionally talk. J did keep her promise for awhile, but  finally told V. Fortunately, V has learned over time that J is slightly  unstable and slightly untrustworthy, so I'm able to deny it and get away with  it.
          
              The only hiccup? J has  had a child, with an age very close to what C should have been. Unfortunately,  I can't really ask too many detailed questions about J's child without raising  V's suspicions. I know I shot the first spurt inside J, and the age is close  enough that I'll always wonder...
          As of this writing in early July  2007, V and I are still together and raising C together. I doubt V and I will  ever have a child together: I was probably too forceful with V when I tried to  get her pregnant in the high school, and she won't touch me at all if I don't  have a condom on. I still don't know anymore about J's child; the few times I  tried to raise the subject, V got suspicious. So I may never know...