Erika tried lifting herself from Emily's softening penis, which came out with a wet pop. The two friends scrambled to cover themselves, pulling down their skirts over their thighs. Someone came down the stairs and stopped.
"Whose panties is that? Anybody there?"
Emily and Erika recognized Piper's voice, one of girls from the loose group of friends they had with Melissa. Piper came forward and spotted the two girls standing up from under the stairs with their shirts unbuttoned and tits exposed. Erika put herself in front of Emily protectively.
"Ew, what are you two doing in there?" Piper called out, wrinkling her nose. She crossed her arms over her chest, which immediately reminded Erika of how Piper and Riley too got exposed to the vial that fell in the pool - Piper's shirt was starting to look too small for her curves.
Erika and Emily finished buttoning up their shirts and came out of the shadows.
"None of your business!" Erika snapped, as Emily's cheeks were turning red.
"Were you playing with each other's boobs? Gross!" Piper taunted.
Erika was boiling. "You can talk! I saw you with Riley at the sleepover!"
Piper immediately looked very serious and upset. "Shut up! I don't know what you're talking about!" she lied.
"I saw you two kissing when everybody else was sleeping and rubbing your parts together!" Erika lashed out.
"Don't say it out loud!" Piper panicked. "I promise I won't tell anyone what you were doing under the stairs if you don't repeat it to other people!"
Erika calmed down a little. "Okay. If you want to keep your reputation then forget about what you saw."
Piper let out a frustrated grunt and left the scene without a word. The two friends picked up their panties and put them on. Emily let out a small whimper.
"Are you okay Emily?"
Emily lifted her skirt, the panties half-way pulled over her groin, which had not shifted back to girl parts. Instead, her one incher had grown to two inches total, and it also looked fairly plump at this point even though it was soft.
"Why is it not gone completely?" Emily asked in a tiny voice. "It looks bigger..."
"I.. uh, well... I think that happens when you put your goo in someone's belly... I'm-I'm sorry" Erika stuttered, realizing she had made things more complicated for both of them now. "But I'm sure it feels more comfortable now than when you were tenting your skirt with your hard pee pee, right?"
Emily nodded weakly.
"And also, when mine will grow back, you can drink my goo and then you can turn back into a full girl again, I promise!" Erika added, which did seem to make Emily feel better.
Fortunately, two inches did not make much of a difference in Emily's panties with the skirt covering it up, so it would be easy to stay hidden, Erika thought. And when herself would get home, she could spray her crotch with more of the salve to make sure she did not get impregnated by Emily just a minute ago.
There was no time to waste though, and the two girls headed back to class after making sure there was no obvious moist spot that would give them away. As Erika distractedly listened to the rest of the lesson, she couldn't help but pass her hands over her bloated belly. The feeling intensified over lunch, and Erika noticed her boobs were slowly becoming overly sensitive.