Was Zoe not in Jon's body anymore? If that was true, then she must have swapped bodies with the other person in the room, which was their mom.
Jon slowly approached the body of his mother. "Zoe?"
She grinned wildly and spun around in a "victory dance". "Fuck yeah!" she yelled out. It was weird hearing his mother (well, his mother's voice) talk like that.
"What ... what's happening?" asked Jon's body, who he now knew was actually his mother.
So now, Jon was in Zoe's body, Zoe was in their mom's body and their mom was in Jon's body. Things were getting weird.
"Now I can do whatever the fuck I want!" Zoe yelled out in triumph. Then she ran away and up the stairs, probably back to her bedroom.
"Zoe, wait!" Jon yelled out.
"I demand to know what's happening!" his mother screamed, tears forming in her (Jon's body's) eyes.