an astounding transformation (слэш)

Yuri kept his head down, but Otabek could still see the flush spreading on his face and down the side of his neck. At Otabek's feet, two tentacles climbed and rippled over each other in what he assumed was a nervous gesture but which looked like— like snakes mating, and oh, that was a bad thought to have right now.
“And now that it's started,” Yuri continued, “I can't shift back until I…”
Otabek took a wild guess. “Until you work it out of your system?”