Amanda turned back to the door leading to the kitchen, opened it slightly and stuck her arm through the crack, giving her friends the thumbs up.

“Alright boys, let me introduce you to Bethany and Sarah.”
These names were familiar to Robert; he had met them both before and knew they were nothing special. He opened his mouth to call Amanda out on her apparent lie, but he was left speechless as the two amazons strode into the garage. Bethany took a position to Amanda’s left, while Sarah stood to her right. Robert immediately recognized their faces, but was completely dumbfounded by their size.

Eric and Jason, however, had never met either of these girls. Like Robert, though, their mouths hung agape at the sight of the two gorgeous, unbelievably muscular girls. They were particularly entranced with what were probably the most ample sets cleavage any of them had ever seen.

The staring continued for a while, with only the sound of terrible top 40 rock breaking the silence. Sarah strutted over to the stereo, waggling her hips as she did so, and turned the volume down. “I hate that band.”
Amanda snickered as Robert started over toward the stereo. “Hey, who do you think you are? We were listening to that, turn it back on or else –“

Sarah interrupted him mid-sentence, a cocky smirk on her face. “Or else what?” She placed her hands on her hips to try and look more intimidating. It worked.

Robert stopped in his tracks and examined the situation in his head. Those arms did not look like they were for show, and this giant version of Sarah had a few inches of height on him too. His gaze drifted toward her breasts, the outline of her nipples still easily visible through the black shirt.
Sarah smiled at first, enjoying the ogling, but then tried her best to look stern and serious. “Hey pipsqueak – my face is up here.” She reached out and grabbed his chin, forcing his view up toward her face. “So, what were you saying? Turn the music back up or you’re going to do what to me?”

Robert shook his head and rubbed his eyes, then looked over at Amanda. “You seriously expect me to believe this is Sarah? I saw her last month and she was just a blobby as ever. This is impossible.”
His gaze snapped back to Sarah as she grabbed him by the scruff of his shirt and lifted him off the ground with her left arm. “Oh, it’s me alright. I’ve just been working out. A lot. No more blobs, just bulges. Oh, and big beautiful mounds.” She used her free arm to force his head between her cleavage. “See?”
Robert’s voice was muffled until she pulled his head out. “Hey, um, hold on a second, I didn’t mean –“
“I know exactly what you meant.” Sarah released him from her grip. He landed on his feet, but did so awkwardly and fell backwards onto his ass. All three of the girls giggled as he scooched helplessly back toward his friends without standing up.

“B-but… how did this happen?!” Robert exclaimed, still seated.
Amanda answered. “She just told you. She’s been working out a lot, her and Beth.” Bethany flexed her right arm, the 25-inch biceps creating a small tear in the fabric of her shirt sleeves. It looked like it was painted onto her shoulders.
All of the eyes in the room were on Bethany. “We’ve made a lot of progress, don’t you think?” she said innocently. “But right now we really wanna work out here.”

Amanda chimed in. “So, how about a little competition boys? Girls vs. guys. Whoever benches more combined weight wins.”
At first Robert thought the idea was ridiculous, these girls were gigantic. But then he thought about it a little more. Even if Sarah and Bethany were clearly stronger than him, Amanda was as scrawny as ever. Jason, Eric, and himself were all in pretty good shape, and he thought that the three of them would probably be able to lift more combined weight than the two girls. Amanda’s contribution would be negligible, with her pipe cleaner arms.

The guys huddled for a few seconds, whispering amongst themselves. Jason didn’t want any part of it at first, but after Robert explained his logic to them and padded their egos a bit with a 'we can do this, guys', the three of them came to an agreement. “Alright Amanda, you’re on. How many reps?”
“Just load the bar up as much as you can and then press it,” his sister responded.
“But what does the winning team get?”

Amanda smiled wickedly. “You’ll win the same treatment that these two girls got.” She knew there was no way they'd decline a chance like this.
Bethany bent over and whispered into Amanda’s ear. “Is that really a good idea?”
Amanda dismissed her friend’s concern. “You saw Sarah move that huge desk earlier, right? You two aren’t going to have any trouble outlifting these three clowns.”

The three guys were suddenly very pumped up about this contest. They had no idea how Sarah and Bethany had gotten so strong, but it had clearly happened *somehow*, and it had obviously happened too quickly for exercise or steroids to be the cause. Whatever the secret was, they wanted to know it.

“You girls are going down,” Eric blurted out confidently. At 6’3, he was the tallest of the three guys, and probably the strongest as well. He was the first to go, and packed as much weight onto the bar as he felt he could handle, then added a bit more. He clenched his teeth and groaned, but just barely managed to lift the 300 pounds of weight over his head. Jason and Robert could not manage as much weight as their friend, but the final total still came to over 800 pounds.

Eric helped Robert rack the weight, and Amanda’s brother sat up, his face beet-red from the exertion. “Alright ladies, let’s see you beat that.”

Sarah yawned. “Alright, I’m first.” She bounded confidently over to the rack, her breasts bouncing as she did so. “Move aside, boys.”
Robert and his friends each grabbed a seat as Sarah began adding more weight to the barbell until there was no more space for the plates. The load had to be well over 500 pounds. Immediately, Robert began to regret taking the bet.

Sarah spit into her hands, rubbed them together and laid down on the bench, placed her hands on the bar and lifted it effortlessly. The guys were stunned – this girl was lifting more weight than any of them had ever hoped to, and she was doing it with the same ease that one of them might lift an unloaded bar. She repeated ten reps and then re-racked the weight, sitting up straight without any signs of exertion. A smug smile was on her face. “Alright Bethany, you’re up next!”

Sarah brushed her black hair out of her eyes and got off the seat as Bethany came over, spanking her friend as she bent over to inspect the weight. “Show ‘em what you’re made of, tiger.” Bethany craned her neck around and grinned ear-to-ear before answering. “I’m made of the same stuff as you, you know that. Which is unfortunate for these guys.”
Bethany thought about taking some of the weight off, but decided she could probably handle the same amount of weight as Sarah. She laid down on the bench and placed her hands on the barbell. Although she struggled slightly unlike her larger friend, she still managed a few reps before re-racking the bar and standing up.

“Sorry boys, we win.” She brought her arms down into a most-muscular pose, as if to further intimidate them. “Looks like you don’t need to lift anything Amanda.”
Robert looked completely dejected, but this look was soon replaced with fear. “Wait, you never said what would happen if you won. Are you going to...” he gulped mid-sentence before continuing. “… make yourselves even BIGGER?”
Sarah answered him. “We’re big enough. I think it’s time for Amanda to buff up a bit though, don’t you think?”
“I’m with Sarah,” replied Bethany. “It’s about time you got into shape.”

Amanda grinned and stuck her hand into her front pocket, producing the growth device. She handed it to Sarah and then pulled off her sweatshirt, revealing her pink and white tanktop.

“What is that thing?” Robert asked, pointing at the device.
“You’ll see,” replied Amanda with a wink.