I sat at my desk in the gym. It had been good to take some time off, but now I was back after 6 mont

I sat at my desk in the gym. It had been good to take some time off, but now I was back after 6 months with a brand new workout regime and a whole new diet planned for my gym comers.

Two girls were doing sessions in the gym that morning, but I was going to be late, so I had left Natalya and Katerina preparation instructions for their special protein shakes. I had picked up the recipe in my travels to South America, and it had a whole blend of rare plant extracts, as well as whey protein from a unique cow breed from a mountain region. It was extremely expensive, but the gains I had made within the last 6 months, without even having proper gym equipment, were a testament to its marketability.

I looked at myself in the mirror. I looked good now, trim and I’d gained almost eight pounds of muscle. The slight side affect made its presence known then, and I quickly sat behind my desk to hide my sudden raging erection.

It was then that I noticed the instructions had fallen behind the desk. Oh crap, I hope they had managed to mix it alright. I checked the cupboard. SHIT! They had taken the whole stock! That was worth thousands! I quickly got up to go after them, when my phone buzzed.

It was Katerina. She was in the locker room and removed her shorts for this one, to show the edges of her new quads. I was impressed - it seemed she’d made some serious progress since I left. Slightly risque photo though. I zoomed in to examine her-

BUZZ

Natalya’s message popped up now.

“Like it bigger, boss? ;)”

And she was. I could see Natalya’s glutes standing out further, and her lower bicep had made significant gains in the last-

Buzzzzz buzzzzz

2 more from Katerina. I flicked to those pictures, and my eyes widened.

In the moments between which she had taken these 2 photos, I could see her abs ripple and harden, standing out further. Now that was one flex trick–

Another photo popped in and, to my shock, I could see an eight pack had literally formed where none had been before. I gasped as I also saw her guns had swollen to almost twice their size between the pictures. She was winking in this last one and blowing a kiss. Against my will, my erection sprung out further…

I had to get up and go and stop them wasting all of the– BUZZ

Another photo from Natalya

“Am I GAINing you approval, sir?”

Holy fucking shit. Her leg muscles had contorted and thickened. Her ass was now densely packed glute, toned beyond imagining. She was massive. Her v-chest showed large rippling slabs of muscle now covering her chest, every inch defined, as if she had been professionally bodybuilding for over 10 years. Her arms looked sculpted from granite, like they could crush rocks. Then I noticed. What the… I mean, the flirting had been one thing, but she was literally giving a shake weight a handjob in this pic. Natalya was seriously up for it. My cock stirred in arousal, and then I realised. The side effect… They had consumed ALL of the product!

BUZZ 

“Hah, not bad, Nat. But - THIS - is swoll.”

Katerina was… bigger. Not just more muscly, but actually larger. Her panties had grown super tight on her, stretched to its limit as she stood on the stairs, and her shirt was practically bursting from her chest trying to burst out of it. I could see her shoes had torn, and toes were exposed, and her stride now covered 4 of the steps up from the locker room downstairs. She had put on a huge amount of bulk, and though she wasn’t as defined as Natalya, she more than made up for it in the size of her muscles, along with her bizarre actual growth…

What the fuck was I going to do?

BUZZ

Natalya was striking a sexy pose, and I could read the caption “Get me a band aid, cutie, because I am CUT!”

And indeed she was. All her muscles strained as she lifted the… the machine. The blood drained from my face, directly into my cock. The photo was taken from Natalya’s feet and showed her lying on the floor. I could see her enormous biceps, dwarfing her head in between them, holding the bench press machine aloft above her head. Her legs were splayed from side to side, and she had either outgrown or ripped off her shorts, which lay in tatters around her, putting her pink glistening pussy on display.

Why was I still sitting here? I should call someone or do something!

I heard a crash, and the floor rumbled. Then a second rumbling began, rhythmically like giant… steps. A picture appeared on my screen.

Katrina was gigantic. Her head was banging the ceiling in this photo, and her hulking muscles rippled in the still. Some of the screen was covered by an enormous thumb, obviously difficult for her to take the photo. She had managed however to type out “bigr” before sending it. Her shoulders were swollen and her arms were like kegs. Somehow, her boobs were still showing atop the powerful broad chest, and I could see the edge of a hard nipple just above where her thumb obscured the photo.

Suddenly a voice shook the entire building

“He’s MINE, SLUT!!” boomed Natalya.

“Oh, PLEASE, bitch, like you have a chance!” sneered Katarina, her voice thundering like a jet engine

A roar of anger, and the sound of splintering wood as something huge was thrown and came crashing through the wall.

I cried out in terror and leaped to my feet, but not before my still swollen erection banged into the desk painfully. I rubbed it, trying to soothe it, when the rest of the wall came down.

“Careful! You nearly broke him!” Natalya said, defensively as her titanic muscles carved through the wall, through the dust I could see a form that made the Hulk look puny. 

“Oh shit! I’m sorry… Why don’t we share?!” said Katerina, her tone thick with lasciviousness. 

“Mmm… if mister boss doesn’t mind and thinks he’d like us both.” replied Natalya

“Oh, he’s GONNA like it.” came Katerina’s voice, and I heard the ceiling crumble under her.

Never mind the thousands from the drink, or my gym being destroyed. My cock throbbed persistently, and I saw a large hand reaching through the dust cloud.