Kyle had been playing out the idea in his head. He had expected Jen to try to turn it on him despite saying any attempts to transform.
"Honestly, Jen. You are more stupid than I thought. Transform or Dare? Did you forget that I--" He stopped, and held a hand up to his mouth--the words had jumped out without his even thinking about it, or even wanting it.
His pants were starting to feel tight, like someone had put his balls in a vice.
"No. NO. I said that you couldn't do that!"
"No, you dipshit." Jen said. "You gave me this ridiculous gross transformation, and then said any attempt to fix it or get revenge would fail. That's not a transform. Transform, by the way."
"But the dare--" Kyle had to unbutton his jeans, it was either that or scream and either pass out or throw up. His cock erupted out like an obscene party streamer, leaping out of his pants and flopping almost down to his knees and still growing. Maybe he could have fed it down a pants leg with time and patience, but his balls had swollen to the size of grapefruits and were nearly crushed.
"What dare?" Jen asked. "The one where you made me strip and get off? That was your dare. You demanded a sick little show you weren't even there to see."
Kyle tried to look down at his dick, but it was a view rapidly blocked by tits--his nipples puffed out, forming peaks, then mounds.
"For your transformation, you'll turn back to normal." Kyle said, the words pouring out of his mouth. "What you were before I called GODDAMNIT it wasn't supposed to be like this!" His cock continued to grow, but now that seemed to be with an erection; as it lifted Jen could see its tip do exactly what hers had done this morning--the tiny opening puffing like rising bread, splitting further, and forming a tiny clit at the top.
Jen didn't need to watch her own transformation reverse; she could feel the bizarre horse-sheath under her skirt fold and twist, swallowing the oversized dick forever. She felt a little more awkward as her breasts shrank down; her clothes seemed to adjust a moment later, but for a half-second there was an unsettling breeze between her nipples and her bra.
"There." Jen said. "That's a lot better."