Jon just didn't FEEL like passing out, he actually did. When he regained consciousness, he realized how weird things had gotten. The first thing he noticed was that he couldn't stand. His head was simply too heavy -- though actually it was because his body was too small. His head was now perched upon the Karyn dildo. He could see Karyn's small dildo-sized head now atop his rubber body.
Zoe and his father now appeared to be one person. She was one girl, the left half of her was a goth and the right half was a ditzy blonde, split perfectly down the middle.
The only other person he could see was Mikey. He was still eighteen and still male, but he was now wearing his mom's lingerie and painting his nails. He must have somehow screwed himself up after messing things up for everyone else. But maybe this could now be Jon's chance.