Keep it as is and see how far she can take it.

"Are you kidding me? This is great! Why would I want to change it?" Samus was bewildered. Couldn't the AI see how wonderfully amazing her ass was? More of a good thing could only be better. Why would she ever want to get rid of it?

Now that she knew she could turn her hills into mountains, Samus was focused on getting as big as she could. As she was going to make it feel good. She had an idea of how she was going to do just that.

"Computer, will you deliver me the biggest dildo that can fit inside me? I know you must have some, you seem to have everything in this facility."

"You are correct, Miss Aran, and I will send a drone to deliver you one in a few minutes."

"Thank you." Samus walked over to a particular set of weights she had spied earlier. They were dynamic weights, advanced equipment that could automatically adjust themselves to the user's strength. They were just the thing she could use. She picked up two large, round plates and a barbell, then found a clear area in front of the reflective wall.

By this time, a small drone entered the gym, rolling on its wheels toward her. A myriad of arms ending in a variety of instruments were attached to its body, one of them holding the item she had ordered: a large, pink dildo, modeled after a human penis. It was a good foot long, and probably three inches thick. Samus blushed in surprise, she didn't think she could take something so large, but if the AI insisted, she was going to try.

"You, little one." The drone snapped to attention. "Please affix that thing to this spot, so that it is pointing up." She pointed to a spot on the floor, a few feet away from the mirror.

The drone beeped in acknowledgement and complied, first setting the toy down, then using one of its many arms to glue it in place. Having done its job, it wheeled out of the room, off to do some other task the AI needed.

"Now, the fun really begins," smiled Samus. Her suit, seemingly aware of her intentions, opened a hole in her spats, exposing her snatch. "How convenient," she giggled.

She lifted the barbell up above her shoulders and placed herself in squatting position over her new toy, facing the mirror. On cue, she felt the barbell grow heavier as the plates adjusted themselves to her power. Most human strongmen would find themselves impressed at the weight she was taking on. She looked at herself in the mirror, focused on what was to come. "Time to get in a real good workout!"

She lowered herself down, slowly, letting the dildo ease into her pussy. "Ohhhhh~, this is almost too much!" She had never taken in anything quite as large, before, and it was definitely a tight fit. She moaned as she felt more of the artificial cock slide into her. She stopped to catch her breath as she reached the base.

Then she went up. Then down. Up and down and up and down. She groaned in exertion and pleasure as she felt the dildo thrust in and out of her. Then, eyes fixed to her reflection, she saw it. Her thighs were thickening. Her hips were widening. Her ass was filling out a little more with each squat. It was like her lower body was being filled with jello, and she was the pump.

A fire lit in her eyes, and she felt a calling like she had never felt before. Her butt was the greatest thing she knew. It was her desire, no, her mission to make it grow, to turn it into the most amazing thing in the galaxy.

With new energy, Samus squatted as fast as she could. Her ass cheeks quaked with her speed, and with each quake they were bigger. They continuously swelled further as she pumped away, straining her legs as much as they would allow. She moaned with the growth, loving the feeling of the added weight behind her. The dildo beneath her dripped with her natural lubricant as she came again and again. As her legs grew more powerful, her weights increased, keeping the growth of her booty at constant pace.

"Yessss! Bigger! Fatter! I'll have the fattest ass in the universe!" Samus was on a one-track mind. Nothing else mattered to her except her cushy, pillowy ass. It was as big as a couch now, and it was still not enough. Her suit spats were making a valiant effort to stay in one piece and contain all of that meat, but it was a battle they were losing. With each inch gained, more tears appeared. Her flesh bulged out of them, widening the holes as she pumped her booty bigger.

"I'm so fucking big! I'm so goddamn sexy! I'll outgrow this gym, then this station, then everything else!" It had gotten so big that it was constantly in contact with the ground. The two hills rose higher behind her as her aspirations rose with them.

But with the increased size came difficulty. She was fighting the very ass she loved to lower herself down. It was her own soft throne, and with every pump, she reached a little less far down. With every bulge of new booty meat, she had less distance to lift herself. Soon, her squats barely counted as such. She desperately tried to keep going, but her efforts were in vain. She was too big.

"No, please. *pant* I must get bigger. *pant* I can't be done yet..." Samus dropped the barbell, which formed a small crater as it hit the floor, and leaned back into her titanic ass. Resting on the round, it was slightly taller than she was. It felt so soft and malleable, it was like she had her own personal water bed. She closed her eyes and gave a contented sigh. She wasn't nearly big enough in her opinion, but this would do for now.

Exhausted from her second workout, Samus decided a nap sounded very good. She could decide what to do next after she woke up. She drifted off to sleep, entertained by thoughts of having an ass the size of a planet.