Hi. I’m Sarah and this is the story of how my relationship with my boyfriend Jacob changed forever. We'd been together for almost two years at that time and started dating while we were still in college. I was 5'6 with dirty blonde hair and blue eyes. A pretty average build -- C-cup breasts and a nice bubble butt. For exercise I mostly did cardio at the gym and a weekly Pilates class. Jacob always wished that I would put a little more effort into trying to lift weights but he was glad that at least I exercised a little.

One fateful day, I came home from my job at the Pharmacy and showed Jacob two pill bottles from a company called GrowTech.

"Hi honey! Check these out, someone left these on the counter today, but the weird thing is I can't seem to find out who left them. And I checked with the other pharmacists, none of them have seen this brand before!"

Jacob looked over from his work standing up. He was 5’8, just a couple inches taller than me.He wasn’t that athletic, but went to the gym every now and again to keep up some form of muscle mass.

"What are these?" he asked as he picked up the pill bottles. All they said was Growtech, womanly enhancement.

"I tried looking them up online but couldn't find anything. Look at the pills though -- one says BE, another AE, and this last one just says MG... what do you think that could mean? And what does 'womanly enhancement' mean?"

"No idea, I bet it's some snake oil crap someone got scammed into buying. Jesus, I've never even heard of half of the crap on this bottle"

"You're probably right..."

I put the bottles on the counter and began making dinner. As I cooked, though, the pills kept popping into my thoughts, wondering what they could possibly do. They certainly didn't seem dangerous... what's the worst thing that could happen? While Jacob wasn't looking, I took one of each pill and threw them back with a swig of water.

The next morning, I woke up with a surge of energy. I decided to go downstairs and get a little workout in. Jacob came downstairs and found me riding the stationary bike that had been collecting dust for months.

"Morning, Jacob! Looks like you finally decided to get up, sleepyhead."

He yawned and checked the clock on my phone, which read 6:30AM.

“What are you talking about? It's only 6:30! And since when did you start using the stationary again?"

"I don't know, I just woke up feeling energetic! I've been on here for 30 minutes already and I'm planning to head over to the gym today. I finally worked up the courage to try doing some of the free weights. Nothing crazy, but I figure it can't hurt."

I hopped off the bike and wiped my sweaty forehead with a towel.

"Huh what got into you babe, someone spiked your coffee with cocaine or something?"

"Haha maybe."

I tugged at my sports bra, noticing that the straps were digging into my shoulders a bit. I quickly forgot about that, but it should have been the first sign of changes to come. I gave Jacob a kiss on the cheek and told him I was headed off to the gym to finish my workout.

At the gym, I walked into the locker room and felt a sense of anxiety welling up inside of me. I had never done weight training before and didn't want to make a fool of myself. I thought back to the GrowTech pills from last night and decided to take one more of each, but when I shook them into my palm, two MG pills accidentally fell out.

I started my workout with some bicep curls, using 8-pound dumbbells. By the end of my second set, I had barely broken a sweat, so I upped it to 15 lbs. That was a bit more of a challenge, but I felt strong, so I grabbed a 20 lb dumbbell and repped out 5 curls.

Next, I hopped from machine to machine, testing out how much I could do. Overhead press, tricep extension, lat pulldown, each one felt more invigorating than the last. I checked my watch and realized it had been almost two hours since I got there! I quickly changed in the locker room and then drove home, unaware of the changes that my body had undergone since that morning.

Meanwhile, Jacob was at home dicking around online, mostly gaming, but after a few hours he began to feel horny. He decided to open up his hidden folder of female bodybuilders and heard me get back home halfway through his jerk off session. He quickly shut everything off and headed over to greet me with a prominent boner.

“Hey babe, how was- holy shit Sarah!"

"What?" I asked, still unaware of my transformation.

He gestured to my body, and I took a look in the mirror. The sports bra I had worn all morning looked like it had shrunk to two sizes too small. Not to mention, my arms looked like those of someone who had been in the gym for months, perhaps a year, not just one day. I spun around and realized my spandex shorts were considerably fuller too; my ass looked better than ever.

For some reason, these changes didn't concern me too much

.

"Wow, I guess I got stronger already! Hmph, who knew it was so easy to build muscle? I have to admit, this is kind of exhilarating... check out my bicep when I flex it!"

I began flexing my bicep and modeling my muscles. Seeing the look on his face was priceless, almost a mixture of admiration and fear. For so long, he had been the dominant one in our relationship, but in that moment, I felt like I was the one who held power over him.

"Like what you see Jacob?" I noticed his erection and smirked. "There's gonna be more where that came from, since I plan on going to the gym every day."

I stepped towards my boyfriend until we were standing eye-to-eye. Wait, eye-to-eye? Since when were we the same height?

"I'll be honest I'm concerned very concerned,” said Jacob, feeling his cock stir. Although he was attracted to my new body, he couldn’t help but feel apprehensive that something dangerous might’ve been going on.

“People don't just get fit or grow 2 inches in one day, besides maybe during puberty."

"Maybe it has something to do with those Growtech pills? Do you think I should stop taking them? I mean, I feel fine... better than fine, actually"

I wrapped my hand around his dick and began playing with it gently.

"Wait, you took those pills? So they actually work…"

"Mhmmmm and I think I like what they did to me..."

I felt my lust take over and started making out with him. Hooking up felt a bit different, now that we were the same height and I no longer had to look up to kiss Jacob, but it felt just as good if not better. He was eager to get my bra off and as soon as the clips came off and my breasts bounced free, it was clear just how much my tits had grown. By then, they were probably around DD sized, though bra sizes were the last thing on my mind.

The pills gave me a fresh wind of sexual energy and I spent it all on Jacob. It took all of my willpower not to make him cum quickly, since I wanted it to last. By the time we were finished, eh was panting out of breath, but I felt I had energy to spare.

"That was fun, baby. Seems like you're fond of the new and improved Sarah, huh?"

"Y-yeah" Wheezed Jacob. “Maybe it wouldn't hurt to take more pills as long as you don't go overboard and overdose."

"True. Then again, I wonder what an overdose would look like,” I said, laughing to myself.

The next day at the gym I wore an old t-shirt so I wouldn't be revealing my newly grown boobs as much and I didn't have to worry about guys checking me out. I started off the same as yesterday, with some bicep curls, but this time I was able to get up to 35 lbs by my last set. Then I started doing barbell squats, warming up with 95 lbs. That felt too easy, so I bumped it up to 135. Somehow that was even easier than the first set. I loaded up two plates and began my final set.

When I got home, I shared the news of my accomplishment, which astounded Jacob. What astounded him even more was my growth -- I was now about 6 feet tall with E cup breasts and respectable muscles throughout my body. I saw a look in his eye and knew he wanted to have sex again.

"Not tonight, baby. I have an idea."

He had an expression like a puppy dog and began to pout his lips.

"Aw, come on I even spruced up the place to help get you in the mood.”

It was true, the house had been cleaned and there was a trail of rose petals leading to our bedroom which was lit by a dozen candles.

"Welll.... since you did go to all the trouble."

I led Jacob into the bedroom, which was strange because usually he was the one leading me. I threw him down on the bed, noticing how light his body felt. I greedily tore off his shorts and began sucking his cock, fondling his balls with one hand. Every now and then I glanced up and caught him staring down at me, his magnificent girlfriend. Once I felt him getting close to cumming, I popped my head off his dick and straddled him, positioning my pussy right above his throbbing boner. Without waiting for a response, I began riding up and down on his cock, my wet pussy lubing it up. Within a minute I felt his dick explode with warm sticky cum. Truth be told, I was thinking about the gym while we had sex, so I knew I wouldn’t be finishing that night. At least not from Jacob’s dick. II sprawled out on the bed and let him play with my boobs while we chatted. I said,

"So you know how you've got that work trip for the next three days? Well, I thought it would be a fun sexy surprise if We don't talk or FaceTime during the trip and while you're gone, I'll keep working out and taking the pills. Then, when you get home you can see my progress and we'll have lots of fun together. Awww don't get that look on your face, I promise it'll be worth it. And while you're gone, you'll just have to jack off thinking of your strong sexy girlfriend getting bigger and bigger every hour."

"You sure babe, you'll have to spend three days without me helping take care of you.”

To make it up to him, I decided to do various poses of me flexing and showing off my muscles, along with some more sexual poses like one with my legs spread and another of me pushing my boobs together. These pics would help tide him over until his work trip was over.

"That good daddy?"

"Oh definitely, pictures this sexy could make a gay man straight"

The next morning as he was leaving for his work trip I wore my bathrobe, which scarcely contained my new assets and gave him a kiss goodbye. It felt strange having to bend down to kiss Jacob, but that was one of the new adjustments that had to be made now that I was taller. I'd measured myself last night after swallowing a few more GrowTech pills and saw that I crossed the 6'1'' mark. I decided to call in sick to the pharmacy that week so I could solely focus on going to the gym and getting as strong as possible so I could surprise him when he got home by being the biggest, strongest, and sexiest girlfriend I could be. I wanted to take care of Jacob and his needs.

I stopped by the Healthfood store on the way to the gym and stocked up on a few tubs of protein powder and multivitamins. The GrowTech pills were working miracles for me, but there was more I could do. Additionally, I decided to ditch the baggy t-shirt and workout in the clothes I wanted. Screw anyone who felt uncomfortable by my physique, I was becoming a muscular goddess and deserved to be treated as such!

By this point, my workout routine had become engrained. No longer was I mindlessly roaming from machine to machine, I was training with a purpose. I always started with the upper body -- bis, tris, delts, and then chest. Getting an upper body pump going felt great, it made me feel invincible. Even more, I felt more powerful than the other gymgoers, mostly roided out dudes. Day by day I outlifted another one of them and took immense satisfaction in their reaction to a girl putting up higher numbers than they could. And not just any girl, a girl that started three days ago.

After hitting upper body, I did legs. Squats and deadlifts were my bread and butter. Squat was my most impressive lift by far, it was up to 315 on the second day after you left for your work conference. I was deadlifting 365 not too long after that and so it went, a race between my squat and deadlift to see which I could do more of.

All of this caused my body to balloon in size -- my muscles grew in ways I never thought possible. There were veins pulsing out of my biceps and each new striation I noticed on my quads sent a shiver of satisfaction down my spine. My traps blew up to huge proportions and after a loud CLANG I dropped 405 lbs on the ground and looked around the gym. Everyone was staring at me in awe and I knew that I was the most powerful one in the room. My stature alone could have told someone that though, not the fact that I was lifting so much weight.

With the help of GrowTech pills and the supplements I bought, I shot up to 7'8'', an unprecedented height for a woman. I now ducked when going through doorways and because of my width, I turned to the side too. Clothes barely fit me, I would take old night shirts and turn them into muscle tees. The first time I did that, the gym staff eyed me suspiciously, but they never said anything, partially because I think they were too afraid to stand up to the she-hulk that I became.

My breasts were massive, the size of basketballs, and my ass retained a nice shape to it, despite all of the muscle mass I'd added. On the third day of Jacob's work trip, my transformation was complete. People were dumbfounded that such a thing could happen in so little time and truth be told, I was too. But nonetheless, it had, and now the only thing on my mind was waiting to see my man's reaction when he came home and found the house occupied by the 8-foot 342lb muscle mommy he called his girlfriend...

After I heard Jacob's car pulling in the driveway, I crawled into bed and pulled the covers over as much of me as they would cover. He came inside, calling out,

"Sarah! I'm home! Time for me to see how big you've grown, I've been dreaming about it all week. Maybe you're close to six and a half feet tall now, could you imagine that? I hope you're horny because I --"

Jacob’s words cut off as he came into the bedroom and saw the massive shape beneath the blankets. He laughed at first, thinking that I was playing a joke on him by putting pillows under there, but his jaw dropped when I threw back the blanket and rose higher and higher, until my head nearly scraped the ceiling. There I stood before him, my huge figure, pulsing with power. Slowly, Jacob’s eyes traveled over each of my muscles, from my sculpted shoulders to my meaty hamstrings and my flared lats. He gradually realized that this was not a fantasy. It was 100% real. My breasts hung just above his eye level, with my erect nipples pointing over the top of his head.

"How's it going down there, tiny? Like the view?"

"Jesus christ what the hell have you been eating for the pass 3 days" Jacob said, completely shocked by the sight before him, a behemoth of bulging muscles and tits that could probably take up his entire torso. He started to instinctively reach out to the abs right in front of his face, touching them not entirely sure if they were real or not. He felt my soft skin over the thick steel bending muscles that pulsed from underneath.

"You like feeling my big strong muscles, don't you baby?" I teased.

He nodded, stroking my body. I picked him up with ease and held him up so that he could look into my bright blue eyes.

"I have a confession. The other day I found some of your porn on your computer...that female bodybuilder stuff. I thought it was so gross, but now I totally understand why you're turned on by huge muscled women. And just think, you've probably got the strongest woman in the world, right in front of you!"

I sat on the bed and placed Jacob on my lap. My boobs kind of smushed against his face but I liked the sensation of feeling his tiny body pressed up against my massive one. I took off his clothes and held him naked against me.

"Why don't you start off by giving my tits some love, sweetie? Suck on my nipples."

He obeyed and began sucking on my left tit, which felt wonderful. Then his foot slipped down to my crotch and the instant it did, my pussy purred lustfully.

Jacob moaned, lost in the ecstasy of my incredible body, feeling the incredible muscles press against his body, his hands holding tightly to my bountiful breasts that almost smothered him in their pillowy flesh.

"That's it baby. Why don't we turn this up a notch, now?"

Jacob stopped sucking and gave me a massive grin. “Hell yeah babe let's do it"

"What position would you like? With my new size, I think it could be a little uncomfortable to have me crush you hehe"

"Yeah we can't do cowgirl anymore unfortunately, what about doggy style?"

I rolled over, causing the bed and room to shake with my massive weight. I get on all fours and boasted how toned my glutes and hamstrings were as I waggled my butt back and forth teasingly. As soon as I felt Jacob’s big hard cock enter my pussy, I let out a moan. Horniness had been building up all week and it felt so good to finally receive pleasure. He pumped in and out of me, making my ass cheeks clap.

“Fuck, you’re so tight babe. This feels unreal,” said Jacob.

The view from his angle must have been amazing, seeing my massive back muscles and taper at the waist.

Eventually I began getting close to orgasm and I could feel that he was too. He grabbed my hair and kept thrusting, faster and faster. The heat inside of me built up to a crescendo until finally the dam burst and I felt myself cumming hard. I let out a loud moan,

"YESYES JACOB, UNGH FUCK ME, FUCK YOUR GODDESS"

As I said this, he couldn’t control himself anymore and he blew your load inside of me. He rolled off me, panting and I looked over and smiled.

"Holy shit that was the greatest fucking I've ever done" Jacob said, panting heavily, looking at his muscle goddess of a girlfriend.

"I know baby, me too. I love you." I wrapped him up with my big powerful arms and knew that our lives were going to be very different from then on.