They could have refused to answer it, but they didn't refuse. Karyn picked the phone up and said "Hello?"
"Hello, who is this? Is Jon or Karyn there? This is Jon's mother. He vanished from college and I traced him to here...."
"I'm, um..." Karyn, however, didn't bother finishing the sentence, because she quickly hung up the phone. Jon's mother wouldn't recognize 'Yolanda's voice anyway. "Jon! Something's wrong..." Then she realized that a lot of things were wrong. Jon seemed different--and it occurred to her that he seemed a little bit older. More mature. She looked down at herself and she was just the same as before.
"What?" asked Jon. "Just as we were getting ready..."
"Jon, this is bad. First of all, that was your mother. Second, she said something about college...."
"But we're in high school."
"Look at yourself, Jon."
"I'm..." He stood up and looked in the mirror. His face was noticeably older--now completely adult, not teenage. "I've changed. But Karyn, you still look the same..."
Karyn changed back to her normal self.
"Wait. No, you're not."
Jon picked up his pants and pulled out the stone. "I wish I knew why things seem strange.... oh, crap. Karyn, first of all, you have to be 21 to stay here. So the stone made us 21. We're in college now, at least as far as everyone else thinks. Second, the stone changes reality. If you wish you're in a hotel, there's some reason why you're in the hotel--a normal everyday reason that has nothing to do with magically teleporting there. I should have wished that we come here without any change in reality. Instead, Mom thinks that we met up, stole some money, and came here."
"Stole some money?"
"Yeah. We wouldn't be able to afford coming here, so there's some explanation in the new reality of how we got the money. Anway, we just need another wish."
"Hold it, hold it... wishing was how we got in this mess."
"Karyn, I can do it. I just need to wish up some explanation of us being in the hotel that's better than being 21 and stealing money to rent the room."
"Well, what do you suggest?"