"I think you'll like this," Sonya purred. Her tail lashed about behind her, knocking over a few items on the dresser. Neither person paid it any mind. "You're going to grow a long dark blue lizard tail and four matching horns."
Derek could already tell what Sonya had in mind. Before he could say anything, however, his pants tightened painfully. His tail was trying to burst out of them. Before he could undo his fly, it succeeded. He dropped to his knees as a thick blue tail grew from the base of his spine.
"Oh! I'm sorry!" Sonya said. "I wasn't thinking!"
"It's...okay," Derek strained to say. He was still trying to shake off the pain. "I have other pants." His forehead ached with the formation of the horns. One pair grew a foot long from his hairline, and the other smaller pair grew from near his temples. "Just warn me right now if I'm going to need to take anything else off."
"Your shoes and socks. The shirt can stay," Sonya said. "Unless you want to take that off as well."
As Derek hastily untied his shoes, Sonya tossed her hair back behind her shoulders. With its increasing volume, it was becoming more and more difficult to keep out of the way. She raked a finger through the long tresses and found it was starting to become tangled.
"Okay, are you ready?" Sonya asked. Derek had stripped down to his shirt and underwear.
"Ready," he said.
"Your legs and feet will gain muscle and blue scales. Your feet will turn into powerful dragon hind claws."
As the bones reshaped themselves and the muscle built up, Derek grunted. "You remembered my story."
They had traded a lot of transformation-themed stories, but Sonya knew exactly which one he meant. HIS story. The one dream of his he had shared with her and no one else. He told her in vivid detail how he wanted to be transformed into a powerful blue dragon. Both Derek and Sonya had become intimately familiar with every inch of that dragon's anatomy, and thanks to the mind-reading curse, Sonya didn't have to spell out the details for the collar to get them perfect.
"Obviously I can't turn you all the way into it. Not here, at least," Sonya said. "But we can still do something. Now let's see that hair change into your coveted mane. And bulk up a little, would you?"
As Sonya watched Derek's hair flare out and bush up into the white-and-blue mane of his dream form, she pressed herself against Derek's swelling frame. He held her in his powerful arms, which Sonya then willed into dragon's talons.
Sonya continued to change his body into an anthro dragon. Soon Derek was completely covered in scales and had a draconic face, with wide fin-like ears and a blue and white mane that stretched from his head all down his back. His shirt had long since given out under his new bulk, and his tail was so long it was doubling up on itself on the carpet.
Derek was stroking--or perhaps fluffing--Sonya's growing hair. It was past her knees at that point, and so wavy and wild it would have been impossible to comb. Tufts of it were spilling over her shoulders despite her best efforts to hold it back.
Soon the couple found themselves on the bed, looking into each others' eyes. They ignored the creaking protests of the bed frame.
"You know what? You're actually bigger than me now," Sonya said.
"I can shrink if you want," Derek's deep voice rumbled through his dragon snout.
"No...I think I want you even a little bigger."
As Derek's body grew a few more inches in height and size, the lovers embraced among their tangle of hair and tails.