Mary's oral stimulation seemed to do the trick, sending a surge through Tim's body that accelerated his changes. His body grew thicker, squatter as taller, thinner human proportions gave way to something much closer to the panda species he was becoming. And to be honest, it felt amazing. He wondered why he was afraid of this at all, as his face reshaped, his hands becoming thick and paw like. The shirt he wore was suddenly too small, and his broadening torso sheared it off at the seams.
It wasn't long until he felt ready, and stepped out of the pants around his ankles.
"I've changed enough to mate you now," he grunted, his voice deeper, almost a growl.
Mary looked up at him, smirking and nodding her agreement.
"Good, do it," she began to turn, and no sooner than she had than Tim was atop her, inserting and pushing his way in. He felt like an animal. He felt beast like and it was glorious. And for Mary it was even more so, as she had not only secured a mate according to this primal drive within her, but she had done it on her own terms, her own time.