Erika pushed Max out of the doorstep, closed her bedroom's door and turned around, resting her back against it. What was happening to her? She felt so sensitive down there that Max' smallest rub or lick was...
As she looked down on her nightgown, she saw that her mutant happy button was slowly forming a throbbing tent. It was certainly larger than her small thumb now, over two inches and with what felt like a pointy end. Her tummy felt itchy and she could tell the six small nipples were growing back, brushing against the fabric. Her breasts also were expanding and pushing in the dress.
Erika took a deep inspiration and jumped into her bed, hidding under the sheets. She didn't want to think about this now. She set up her alarm for school and shut her eyes close, breathing calmly to fall asleep as fast as he could and not think about the fact she was growing a dog penis again. It took a while but the warm tingling came to a rest eventually, and she finally drifted off.
She could not tell how long she had slept, but when she opened her eyes it was still dark outside. She felt all sleepy and weird, tangled in the bedsheet, and she could hear Max scratching lightly at her bedroom's door. Something was off.
In the dark room, a huge tent was sticking out in the middle of the sheet. Erika struggled to untangle herself from the bed covers and pushed them at her feet, staring.
The dog penis had returned with full force, longer and thicker than ever. It was maybe 7 inches now, with a swelling knot. Her nipples were all erect too, including her human ones; her breasts had grown to a large B cup and spilled out of her small nightdress - which Erika wiggled out of, not without some difficulty.
That's when she realized the full extent of her current condition.
Her tummy and forearms were covered with a very soft, short, cream fur, while her legs and back had grown a thicker, darker coat in tawny brown (it was difficult to tell because of the dark). The pelage was trailling off on her shoulders and face, and her human breasts were still bare so far.
When she touched her head she felt pawpads under her fingers, and very large canine ears pointing up. Her nose had grown more animalistic and wet, and she could feel long, sharp teeth inside her mouth, which she opened to let a canine tongue loll out. She let out a surprised yelp when she noticed a bushy tail above her fluffy butt.
"No... this isn't happening!" she whined as she attempted to step out of the bed, and tripped on her canine feet. Her legs had become digitigrade and she struggled for a moment to find her balance. All the while, her boner was still throbbing, demanding attention. Erika felt light-headed, and opened her door to slip outside her bedroom.