"Well..." Peter grinned slyly. "Joce has been so happy changing me, and I'm enjoying it just as much as she is, but now I'm so large most of the time, and nothing is my size anymore..." He emphasised his point by cupping his hands upright in the air as if grabbing basketballs. Each hand was proportional to his 7' frame, and could cover half a bowling ball easily.
Ty felt he knew what his cousin was getting at. "I see. How about I make it so that you can change Joce, but only if she's ok with it, and do nothing that will cause her harm?" And then a second idea hit him, that would make the ability even more appealing to both parties. "However, every time you change her in some way, you'll grow bigger as well. So if you decide to play with her breasts, you're muscles will increase a fraction. Sound ok?"
Peter grinned. "Yeah!"
Ty snapped his fingers, and Peter suddenly became aware of that feeling he got when Joce was in his head, but now it felt much more two way. Joce's thoughts were amused.
:You know, most girls would feel insecure about their boyfriend wanting to modify them, but luckily I can read your thoughts- you just want me to join the fun, huh?":
Peter grinned and was about to test out his new powers when he felt Joce panic. :Not now! I'm in aerobics class, and trust me, after we showed up together this morning, some of the girls have been staring at me trying to figure out why a god like you is hooked up with me, after school, I promise!:
Peter nodded and sighed.
"She's right, you know- we don't want anyone figuring out what we all can do." Ty's words startled Peter, but figured Ty had been able to hear Joce's discussion. "But after today, everyone will accept however you two change yourselves as the way you've always looked, ok?"
Peter grinned. "Thanks, Ty!"
Later that day, after classes were over, Joce wandered over to the school pool, expecting Peter to be getting ready for swimming practice. She needed to change him back from his living statue body so he wouldn't sink in the pool, she realized. But as she rounded the door of the locker room, Peter grabbed her arm and pulled her into the locker room, which she was surprised to see was empty.
Peter grinned at her confused look. "Coach was sick today, so we've got a day off. Everyone already went home, so we've got the locker room all to ourselves." He emphasized the point by shoving the chair that he'd mangled last time they were in here together under the door, preventing any unwanted visitors.
Joce grabbed his neck and climbed up to kiss her 7' boyfriend hello. But as she was enjoying the liplock, she felt a tingle in her chest. She groaned into Peter's mouth as she felt her breasts expand against Peter's pectorals. She sank into his grasp as she felt the need to touch the sensitive flesh. Her modest B cups had pushed past Cs, spilling out of her bra in all directions. She wimpered slightly as the bra cut into her chest. Peter, feeling her pain, deftly unhooked her bra's front clasp, and moved his hands to cup the growing flesh.
As if responding to his growing desire, Joce's breasts jumped in size, filling each of his hands and still growing- they didn't sag, defying gravity with the help of Peter, who now began kissing and suckling the ever expanding flesh. Each button of her shirt strained and burst, but Peter didn't notice the buttons bounce off him.
In fact, he was so entranced he failed to notice his own growth triggered by Joce's change. His tank top had torn at the seams as his body pushed out in every direction. His pectorals pushed up and out, and his abs widened and bowled out, as if Peter was about to himself burst with all the muscle packed onto his frame. his shorts were in tatters, both from the oak like trunks of his legs and the literal python that now too began to massage the silken skin of Joce's breasts.
Finally the accumulated frenzy of growth became too much for both libidos and they climaxed in mutual pleasure.
Joce opened her eyes, surveying her new chest. the twin hills now attached to her were beyond her knowledge of cup sizes, but she'd guess at triple h cups, well beyond anyone else on earth, real or silicone. She wouldn't be able to stand with them, if not for the magic and Peter's help. Her shirt (thankfully one she'd been planning on throwing out soon anyways), had every button burst, unable to even begin to contain her.
When she looked to Peter, despite their previous changing games, she still stared in wonder. He was practically square- not refrigerator sized, but larger, like four stuck together! He practically looked like he'd swallowed a minivan. His pecs, glistening with sweat, rose and fell like bellows, which bobbed a penis with a head the size of both her fists. It had to be twenty inches at the least. She couldn't see past herself to see below, but there was no doubt he was massive through and through.
Suddenly a low growl shook him and her flesh pressed up to him. Peter absently rubbed his abs, and Joce suddenly remembered Peter had had to skip lunch to study for a physics exam. She grinned at him. "Guess the big boy's hungry?"
Peter nodded, rubbing her breast gently. "Guess since all of me grew, so did my hunger."
"Growing boys have growing appetit-" She trailed off as a gleam appeared in her boyfriend's eye. Suddenly the tingle was back, as her breasts began to plump further, gaining a much more fuller look. It was a she felt them filling did she realize his plan. "So you're on a liquid diet?"
Peter just grinned as he tipped one practically spherical breast up, and began to drink....