Mackenzie

"Professor Gunnarsson, if I don't do well in your biochem course, I'm not ever going to get into medical school".

I can't say I hadn't seen this one coming. Ever since the mid-terms Mackenzie had become remarkably more visible in class, occasionally appearing in a skirt and heels, and moving to the front row. No college junior these days would ever be seen in a skirt, much less heels, unless it was for a prom or some other major occasion. She brushed off the odd looks of her fellow coeds with the attitude that she could damn well wear anything she wanted, and was it, after all, more outlandish than some of their outfits? If they wore goth with elaborate piercings and heavy makeup (or no makeup) and sported other strange looks to make themselves "different", why shouldn't she? Was a skirt and heels in class any less outlandish? As for the male students, they for the most part had no idea what to make of it. Some clearly loved to look at her, while others simply ignored her, and a few just managed the occasional covert look as if afraid to reveal what they were so obviously thinking.

Given that she had moved to the front row, ignoring her was not an option for me.

I could have taken it as a not-too-unusual play by a young coed for an attractive older faculty member. I'm not in fact all that old, and I'm not hard on the eyes. My Icelandic background gives me an athletic build and sandy-colored hair, and it makes me pretty exotic in the eyes of most Americans. So it could have been a play for attention, or maybe an attempt at a conquest and another notch in her belt, but the timing was all wrong. Aside from her astounding beauty, nothing in her behavior had set her apart from the other students until she began to do poorly on her exams.

I had, of course, noticed Mackenzie from the first day of the term; what male would not have? She was tall, athletic, with long dark hair and beautiful dark eyes. Even in the shapeless clothes that undergrad women affect, you couldn't miss her spectacular breasts, her narrow waist, and her long legs.

Curious, I looked up her unusual name. It turned out to be very apt: "Mackenzie is a Scottish name with Gaelic roots. Derived from the Gaelic surname MacCoinnich, Mackenzie means 'comely,' 'attractive' or 'pleasant to look at.'" Talk about spot on!

The first time she showed up in class in heels and occupied a front-row seat, I nearly lost it. I had a hell of a time keeping my eyes off those long shapely legs and my mind on what I was lecturing on. When she crossed her legs, I had to turn to the blackboard to gather my wits. I tried to pretend to myself that she was dressed that way not for me but for some lucky guy and it was none of my business, but when I did turn to the class again, she smiled directly at me with a look that said that she damn well knew what I was thinking, and it wasn't about the Krebs cycle. I can't remember how I got through the rest of the lecture, essentially on autopilot.

For the next class she appeared as she always had before, so I could collect my thoughts and keep my mind on the lecture. Well, most of my mind, anyway. My eyes kept drifting toward Mackenzie as if hoping to see her as she had appeared before, but she sat demurely, fully occupied with taking notes. Then, a couple of classes later, there she was again, looking so mature and radiating sex. But by then I had learned to dial down my instinctive response by using the mental crutch that her choice of apparel had nothing to do with me.

But now, here she was in my office, so vulnerable, so desirable. My defense mechanism seemed so futile now. I knew beyond a doubt that this visit was the culmination of her weeks-long assault on my professorial armor. What I didn't know yet was whether or not that assault had been successful.

"Mackenzie," I said, fighting for control, "I'm sorry that you haven't done as well in my class as you had hoped. But that's not my fault, now, is it? Everyone in the class took the same exams as you did, and most did substantially better than you. And then, there's still the final to go. You could erase the bad midterm grade with a really good one on the final. And as for medical school, do you really think that your grade in one class is so make or break?"

"Yes," she said. "I do. You and I both know biochem is one of those key subjects the med schools look at."

She looked hard at me. I knew what was coming next. I'd get the meaningful look, and then she'd say that gee Professor, she'd be willing to do anything (heavy emphasis on 'anything') to pass this course.

It didn't work out that way.

"Look, Professor Gunnarsson, I don't want to make this more difficult for either of us than it needs to be. Let's be honest. I've been pushing your buttons for the last couple of weeks, and you've responded exactly as planned. You want me, and, frankly, a lot of people in the class know it too. So, to get my way all I'd have to do is to accuse you of sexual harassment or even yell rape. Even if we fought it out and you won, your reputation here would be trash.

"But there's a way out that's much more pleasant for both of us. You tutor me in biochem until I can ace the exam, and I'll grant your fantasies. You're a good-looking guy, so it might even be fun for me. Since I'll pass the exam on my own and can prove it, nobody gets in trouble and we both win. Look, Professor, I'm not stupid. I can learn this stuff. And you'll find that I'm a willing worker in both jobs."

What could I say? I was gobsmacked. This gorgeous girl was offering to accede to my fantasies about her marvelous body, and in a setup that didn't have a downside that I could see. Sure, Mackenzie was treating sex in a purely transactional way, which seemed a little cold, but I've enjoyed escorts from time to time when I got lonely, away at scientific conventions, and what's more transactional than that? Besides, she had said that she thought it might even be fun for her.

"Well?" she said. "I have to say, I'm a little disappointed that you have to think about this one. Ok, then. Maybe a small sample would help."

Mackenzie looked out into my lab. There was no-one working there. She closed the door to my office. With her dark eyes locked on mine, she slowly unbuttoned her blouse. I knew I should protest, but as her lovely cleavage became more open to my gaze, I was helpless. I could feel my cock straining against my pants. My breath began to come faster. Mackenzie's blouse was fully open, now, and she slipped it off. Her sweet, firm breasts seemed to overflow her cream-colored bra. I couldn't take my eyes off them, they were so beautifully formed. She reached behind herself and unsnapped the bra, letting it fall slowly away. Her breasts were as magnificent as I had imagined they would be. Young, perfectly shaped, surmounted with dark aureoles forming a backdrop for red nipples. God, I wanted desperately to touch them.

Mackenzie advanced toward me. Hopelessly confused by conflicting emotions, I backed away until I came up against my desk. She kept coming, and then dropped to her knees in front of me. She smiled up at me and undid my belt. My cock was throbbing, wanting to burst out. She unzipped my fly and slid my pants down. My professional brain was crying out for her to stop, but my lizard brain was in control. I did nothing.

She looked at the outline of my cock through my shorts.

"Oh, that's a nice one," she said. "I'm going to enjoy this. You just relax and let me do all the work this time. Later we'll put you to work."

With that she reached out and with a long, delicate finger, touched the wet spot in my shorts where my pre-cum had soaked through. She put the finger in her mouth and licked it clean.

"Very nice," she commented. "I like the taste of your pre-cum. I'll bet your cum is even better. Let's find out."

With the last vestiges of control, I managed to say "Mackenzie stop. Don't. It's not right." But even as I said it my traitorous hand rested on her head, tacitly encouraging her.

"You know you don't mean that," she said. "So, you just be quiet and let me work a little magic."

She slowly pulled down my shorts to reveal my stiff, aching manhood. She wrapped it with her cool fingers and brought it down to her mouth. I could feel the warmth of her breath. She leaned in and kissed the tip.

By now both my hands had found their way to her head, and I pulled her closer. In response she just opened her mouth and let me guide her onto my cock. I wanted to grab her head and ram it into my groin, but her complete lack of resistance stayed me. I let her proceed at her own pace.

I felt her warm, soft lips on the tip of my cock. They parted so easily, and I slid into her mouth. I groaned with pleasure. Mackenzie murmured around my cock, "Mmmm. So nice and warm and full. I'm going to like this."

She began to move back and forth, sucking on me as she moved away, swirling her tongue around me as she moved toward my groin. I moaned. Gratefully, I yielded to her. I was completely in her power. I held her head steady and began to probe in and out of her mouth. She offered no resistance. Her hands reached up and cupped my ass. She pulled me toward her, driving me deeper into her. The sounds of her sucking, the liquid warmth of her mouth, the ministrations of her talented tongue all worked to drive me closer and closer to a climax.

"Oh, God, Mackenzie," I sighed. "It feels so good! But if you don't stop, I'm going to cum in your mouth."

She pulled away for a second. My heart stopped. But then she said, "Don't be afraid. I've got you. Just let it come. Let it all come."

She reapplied her mouth to my pulsating cock and sucked even harder. She cupped my balls for a second, and then put her hands back on my ass and pulled me to her. And that was all the encouragement I needed. I gasped and moaned. I held her head with a death grip and shoved into her, deeper and deeper until I was down in her throat. Her mouth and her throat embraced and massaged my cock. I plunged in and out a couple of times and then I felt my balls contract, and I came, hard, into her welcoming mouth.

I just kept spurting, shot after shot into her warm depths, gasping and moaning in ecstasy. I don't know where all the semen came from, but it just kept coming. Mackenzie coughed a little and I felt my own sperm and her saliva on my bare legs. My hands kept her head locked in place while my cock throbbed and pulsed, and I shot my full load into her. She didn't resist. I felt and heard her swallowing it. Lord, I don't think I had ever cum that hard in my life.

At last, I was drained. Both of us stayed motionless as we came to grips with the mighty passions we had released. Reluctantly, I withdrew my wet and still-dripping cock from her mouth. I looked down at her. She looked up, smiling, her lips and chin glistening with my spent sperm. There were runnels of my product on her heaving breasts, catching the light from the window as her chest rose and fell with her breathing.

After a while, she stood up. She took some tissues from my desk and wiped her mouth and her breasts.

"Well," she said. "Do we have a deal?"

It took me several long seconds to piece back together the shards of my consciousness. With a visible effort, I managed to regain at least some of my professorial persona.

"We have a deal. My apartment. Next Wednesday, 8:00 o'clock. Bring the textbook and your class notes. And for God's sake, don't let anyone see you coming there."

Mackenzie was as good as her words. Over the next few weeks she worked hard on her lessons and willingly performed any acts I asked of her. One week I had her give me a long, sensuous oil body rub that culminated in a marvelous hand job. She kissed the tip of my cock as I came, taking it all into her mouth. Another time she dressed in a diaphanous nightie I had chosen while I watched her masturbate to climax. I had her any number of ways. She never complained. No, Mackenzie was not the problem.

I was.

I found myself getting more and more addicted to her lovely, lithe young body. I couldn't get enough of her. When she wasn't there, I dreamed about touching that firm, warm flesh. In her presence it was getting harder and harder to concentrate on my end of the bargain, teaching her enough to ace the exam. Take for instance last week. We were working on the pentose shunt. She was in my apartment, propped up on the bed, dressed modestly in a soft sweater and tailored pants. She had the textbook propped up on her thighs. I sat at the night table. I kept looking at her. I couldn't get enough of the gentle swelling of her breasts under the sweater or the curve of her hips. I loved the frown on her beautiful face as she dealt with the series of reactions in the pathway.

"I don't get it," she said. "Why not simple glycolysis?"

"Because you need it to produce nucleic acids for DNA, among other things," I said.

"Seems like a complicated way of doing it, "she opined. Frustrated, she slammed the book closed. "Besides, how do you expect me to remember all these damned enzymes, anyway."

"Hmm," I muttered. "We need a good way to visualize this. Take off your blouse and bra."

Mackenzie gave me a very puzzled look, but she was pretty used to taking orders from me. I watched carefully as she lifted the sweater up and over her head. The motion beautifully accentuated her breasts, lifting them and deepening her cleavage. She noticed my rapt attention, and smiled knowingly as she unfastened her bra.

"Look, Professor, we're supposed to be doing biochem, here. I get the feeling your mind isn't on that. I'm willing to hold up my end of the bargain, but you've got to hold up yours. If you want to fuck, we can do that later. Ok?"

"Mackenzie, just do as you're told. I'm the one giving the lessons, remember?"

She smiled and lay back on the pillows. She put her arms behind her head, the picture of insouciance. Her breasts glistened in the light of the reading lamp.

"Okay now," I said. "Suppose your left breast is the G6P dehydrogenase enzyme, with its active site on your nipple."

She looked puzzled, but grinned.

"I'm the G6P," I said. "In order to react I have to attach to the active site, right?" I leaned over and put my mouth on her nipple.

"Good," I said. I started sucking on her nipple and tonguing it to hardness. "The site seems in proper configuration. Now I can begin to react."

I stood up and took off my pants and shorts.

"As you can see, I've already begun to react. But we'll need to transfer me to another site, the 6-PGL site, for me to complete my reaction."

I used my lips and tongue to slowly trace a path down from her breast, over her firm belly. I unsnapped her pants and pulled them off. I kissed her pussy through her thin panties.

"We're at the reaction site, but it's blocked. I'll have to activate it before we can proceed with the dehydrogenation reaction."

I slipped her panties down over her sweet thighs. I returned to her pussy and began kissing and licking her clit. Her breath was coming faster, now. I kept probing her with my tongue. She soon grew wet, and her hands gripped my head and pulled me in closer. Her pussy tasted so wonderful, and the musky, pheromone-laden odor of her arousal seemed to go directly into my brain and raise my desire for her to a fever pitch, almost irresistible.

When I judged her ready enough, I withdrew.

"As you see, now the reaction site is ready to accept the reactant. Now the reaction can go to completion."

I climbed up onto the bed and placed my cock against her wet pussy. She gasped and put her hands on my butt. She pulled me toward her. My cock parted her pussy lips easily and slid into her. Oh my God, she was so warm and tight. Her vaginal walls seemed to grasp and massage my aching cock.

Her breathing was very rapid now. I began to stroke into her, going deep with each thrust. Her eyes closed and her head lolled back. She began to moan.

Faster and faster I stroked, my hips bucking while her hands and arms pulled my chest tighter to her. Her moans became little cries of passion in time with my thrusts. I could feel her rock-hard erect nipples pressing my chest. I was ready to cum, but I held off until I judged her ready to receive my load. When it seemed that her legs were quivering and her grip on me was almost spastic, I let go, then, and came into her, flooding her vagina with my hot seed. She cried out, and her hips writhed under me. More and more, I spurted into her, until I could feel my semen backing out of her. Just then she squirted. Oh my, did she squirt! She soaked my groin and the blankets with her sweet juices.

Afterwards we lay side by side, panting, oblivious to the wet pool of our passion under us. When her breathing returned to normal, I said, "and that's how you remember which enzyme goes where in the cycle."

"Professor," she said, "If you think I going to remember my own name after that, much less a reaction sequence, think again."

You see the problem. I knew that I had to properly coach her if she was ever to legitimately pass the exam. But every time we got together, all I could think about was her body. I was obsessed. I just couldn't keep my hands off her. Yet the time for the exam was drawing ever closer. I even began to think seriously about cheating, just giving her a passing grade so we could concentrate on sex, but I knew that wasn't going to work. First of all, I'd be breaking our agreement, and second, I knew we'd be found out. Even if we pulled it off, worst case, Mackenzie would have a powerful hold over me forever, should she decide to blackmail me for some other future gain. No, I had to deal with my addiction somehow.

They say that every addict has to find his or her bottom level, the point they sink to where they realize that going lower means the end of everything for them. For me, the realization that I would risk my job and my reputation in order to have a couple more weeks of sex with Mackenzie was the bottom. It was like a cold shower. I knew then that I had to sober up or lose everything, including Mackenzie. I was pitiful in my own eyes. I needed to clutch the shards of my shattered self-respect to myself and regain my soul.

The next night Mackenzie was again perched on the bed. Lord, she looked so fetching. I could feel my cock stirring again. But this time had to be different, or I was lost.

About an hour into our session with glycolysis, Mackenzie yawned and stretched lasciviously, accenting the swell of her breasts. There was a pause. She looked at me.

"I'm tired," she said. "Can we take a break?"

There was a long pause. I didn't respond.

"Professor, you're different tonight," she said, a question in her voice. "Last week you'd've be all over me the minute I stopped working or gave you any slight hint I might be receptive. What's up?"

"What's up? Mackenzie, the exam is in three days. You're not ready yet. We've got to quit fooling around and get down to it."

She gave me a long, piercing look. Finally she shook her head.

"You don't find me attractive any longer?" she said.

"Mackenzie, you are the most attractive woman I've ever known. I would give almost anything to hop into that bed with you and fuck your brains out. But we have a deal, and I've got to hold up my end of it in spite of all my desire for your fantastic body. You've held up your end and now I need to hold up mine. Now, let's get back to work."

She gave me a puzzled look, but then shrugged her lovely shoulders and just smiled. I like to think she looked at me with a new respect.

A week later I was alone in my apartment grading the biochem exams. Naturally I picked up Mackenzie's first. My smile broadened as I worked through it. Except for some minor points, she had truly aced the exam. Her work was clearly original. No-one could accuse her of cheating or getting special favors.