Jon reached down and touched the empty space beneath his half-erect cock.
"Oh my god..." he said, "why did that happen?"
Karyn shrugged, nearly popping her huge breasts out of the tiny bikini top. "I don't know, isn't it random?"
"It's supposed to be guided by your subconscious desires," said Jon, "and I don't think I subconsciously wanted my balls to vanish."
Karyn remained oddly silent.
"Oh well, everything should go back to normal when we put it away," he said, and played a card that said "6 inches of height".
Karyn gasped as she went from 5'2" tall to a mere 4"8", becoming comparatively bustier and curvier as she shrank. Then she played another card that read "Body hair". Jon couldn't counter it, and he flipped over a card that said "Sexual arousal". His cock sprang to full attention, and he started to sweat. He suddenly felt more turned on than he had ever been in his life.
Barely able to concentrate, he played a card that said "Bikini", and Karyn was suddenly naked in front of him. She put her cards face down on the floor and quickly covered her breasts, and then reached down and pulled a card form her hand.
"Masculinity".
"What?" said Jon, as he looked down at himself. His body seemed... smaller all over, and his muscle definition had faded almost entirely. His chest was narrower than it had been since he had hit puberty. His penis was still hard, but it was suddenly tiny - not more than two or three inches long, and very thin. In fact, apart from his height, it almost looked as though he had never gone through puberty. He reached down and touched his tiny cock, and had to pull his hand away as he nearly orgasmed on the spot.
He played another card; this one said "Shyness", and Karyn didn't have anything to counter it. She stopped trying to cover her breasts, and even moved her legs so Jon could see her pubic hair. She played another card, which read "Penis". Jon's tiny member vanished entirely, leaving smooth skin and nothing else in his crotch. Jon reached down in shock and amazement - he was incredibly turned on, but had no way to relieve his arousal.
He played a card that said "Body hair", and Karyn's red pubes vanished revealing a tight, moist vulva. Then Karyn played a card that said "Belt", and Jon couldn't counter it. He flipped another card that said "Pussy", and suddenly he looked like a completely flat-chested woman.
"That's more like it," breathed Karyn, as she played another card...