Soon after drinking one of her own potions, an aged-up anthro Apple Bloom builds muscle with even the slightest strain. She finds, to her own growing arousal, that even simple chores are making her bigger and stronger than a jealous Applejack's wildest dreams. She delights in making sure Applejack knows that.

“Darn it,” Applejack grumbled. She reached for the top shelf on tiptoe, her powerful thighs straining to keep her body raised. “Where is that kettle?”

She should have known better than to speak aloud. A trio of loud thuds shook the kitchen floor, and she winced when the last one stopped just behind her. Already knowing what to expect and hating it, she glanced up—directly into a giant pair of knockers smushed together right above her head.

“Don’t worry, sis.” Apple Bloom. Damn that filly. “I got it for ya.” A heavily muscled arm, as thick as Applejack was wide, reached over the massive bust and poked around the shelf for a second. Then—”Got it!”

Applejack soured as the arm retreated, a comparatively tiny kettle grasped in its fingers. Then she heard another pair of thuds and the shadow over her retreated. Once she’d taken a deep breath and warned herself not to say anything rash, she could to three, and then slowly turned around.

She looked up. Sure enough, there was Applebloom, her “little” sister turned big. The “filly” was grinning down at her. She’d palmed the kettle and had held it up to about shoulder-level, which, to Applejack, was about a foot and a half too high.

“Thanks,” Applejack said, as politely as she could manage. “But I coulda gotten that myself, thanks.” She waited for Bloom to hand it back down to her. She could have reached up for it and asked, but darn it, that was downright demeaning. She wasn’t about to reach up to her baby sis, no matter how much bigger AB had gotten.

“Don’t worry ‘bout it.” Bloom grinned down at her over the shadow of her enormous bust. Privately, Applejack wondered how she’d managed to even fit those things into the kitchen. Admittedly, Big Mac’s extra-wide chest meant that all Apple doorways were a bit wider than regulation, but Bloom’s knockers were something else. Each one was a good three feet wide, with an erect nipple nearly half the size of AJ’s fist. AJ didn’t doubt that her “little” sister was getting off on looking down on her “big” sis. She wondered how long it’d taken Granny to knit a sweater that could cover even half of those massive tits.

She shook herself back to reality. “Y’all always taught me to help out family whenever I could,” AB was saying. She flashed AJ a smile. “I’m always glad to lend my ‘lil sis a hand.”

That did it. Dignity could go stick itself where the sun didn’t shine. Applejack shoved a hand into the air and held it there expectantly. Apple Bloom chuckled and let the cast-iron kettle drop into her sister’s hand. AJ struggled to hold in an oof as the forty-pound monstrosity dropped into her grasp. Out of the corner of her eye, she could almost swear she could see Bloom flexing. Just one of those biceps had to be bigger than her head! How did a filly even get that big?

She huffed. “Now,” she said, more to herself than anything else. “To get that cider opened—”

“Oh!” Applebloom said, beaming. “I got it!”

“Bloom—wait—” But the oversized filly was already bounding over to the pantry. In one quick motion, her thighs and arms flexing casually, she grabbed a five-foot barrel of cider, hoisted it up into the air—and started to tremble.

“Consarnit!” Applejack swore, reflexively taking a step back. Applebloom was grinning, though, and as her “little” sister watched, the filly-turned-amazon began to grow. Her mane had already been brushing up against the ceiling, but soon she was leaning forward so that her head wouldn’t bump against the plaster. Her breasts surged out even wider, her nipples dampening as the XXXL-sweater was slowly pushed up to just below their height. Her hips widened until they were three times as thick as Applejack’s. Her muscles bulged, surging in size, veins pumping and swelling as their owner grew even larger.

Finally, her growth tapered off, leaving her a good six inches taller than she’d been when the spurt had begun. Applebloom blinked, grinned, then took a step toward Applejack. The floor cracked slightly beneath her weight.

“What was that, lil’ sis?” she asked.

Applejack swallowed, then scowled. “Now, listen here, missy. Y’all can’t keep growing like that?”

“Why not?”

Applejack almost said it, then stopped herself. “I…” she said, her voice trailing off.

Applebloom gave a casual flex of her muscles. She took a deep breath, her chest inflating impressively. “Go on,” she said. “I’m listenin’.” Applejack mumbled something. “Can’t hear ya, sis.”

“Because…” Applejack inhaled deeply. “Because you might outgrow the damn house!”

Applebloom’s smile turned sly, almost predatory. “Well, shucks,” she said, licking her lips. “Can’t have that happenin’.”