Keith put the stone on his desk and got up to kiss Erika, all the while thinking how strange all this was. Erika used to be his best friend. But was there anything left of Eric in Erika?
"Erika? Do you remember being Eric?"
"Of course, sweetie."
"And you're okay being this way?"
"As long as I have you as a lover."
Me as a lover, Keith thought.
Karyn didn't like it that she had to share her girlfriend with Keith, or more to the point, with a guy. So, she decided to fix the situation.
While Keith and Erika were kissing, Karyn grabbed the stone from Keith's desk and said "I wish Keith was a lesbian like me and that me, Erika, and Keith all loved each other."
Keith stopped kissing for a moment. What? he thought in his mind. And then his body became the female version of himself. She went back to kissing Erika.
Karyn tapped her on the shoulder and whispered in her ear "How about you kiss me now?" She then licked her ear.
Kathy (Keith's new identity) stopped kissing Erika and proceeded to kiss Karyn.
Per the wording of the wishes, Erika still remembered being Eric. But Kathy remembers nothing about being Keith.
