Joce grinned at the giant, growing, hyper-muscled Peter on the ground.
But she was feeling left out. She prodded his mind, 'suggesting' he use his powers on her to join the fun.
Sure enough, a tingle started in her chest. Her boobs slowly expanded, first spilling over the top of her bra, then the bottom as well. Slowly but surely her shirt pressed forward as flesh fought fabric.
After a few moments, the straps broke. Then the hooks began to give way. She looked like she was smuggling basketballs under her shirt.
The bra fell to the ground, defeated. Her shirt came untucked, and the seams strained to contained the two watermelons. Despite the lack of bra, the breasts were still perky and rounded.
As the shirt began to rip, Joce's back muscles strengthened to carry the increasing weight.
Finally two pontoons broke free of the losing shirt, resting against Peter's giant growing pectorals...