After a while of swimming and hopping around in the glass confinement with the boy watching utterly amused, he suddenly grabbed Beth, lifted her out of the aquarium and starting toying around with her personally. Beth's spineless struggling to get out of the grip of the boy's hand only entertained him more. "You're cute", he said as he held her by his face and kissed her on the head...which was apparently enough to trigger the magic contingency defined by the spell. However, something that neither Beth nor the boy knew was that because he wasn't a prince, the spell would affect him as well.
The boy's skin started turning green and slimy and a bit lighter at the base, his bones quickly dissolving and his fingers and toes stretching, as his face made strange contortions until he could do no more than croak and ribbit. All the while, as he shrunk, Beth started growing and her changes reversing back to a princess. In the end, a tiny confused frog remained among a pile of empty clothes, princess Beth standing there naked. She picked up the frog and tossed him into the aquarium.
"Thanks, you're cute as well. Unfortunately for you, you won't be seeing this "cute" lady for a long time, and you'll be seeing flies and lilypads until the end of time for all I care. I'm finding some clothes and then I'll leave you here...but first, food for a while." She took a nearby container of black flies and released some into the aquarium, the former boy's tongue now quickly snapping at them and gulping them down. Meanwhile, Beth went upstairs - luckily no one else was in the house - and looked in a few closets until she found clothes that fitted her. She quickly put on some clothes and left the house, leaving behind a croaking male frog for the other house occupants to play with.