"I tried to warn you." Caleb chuckled as he twirled his wand. The purple tendrils continued to seep out of the tip and into his paralyzed boyfriend. Well, ex-boyfriend. "If you got on my bad side there would be consequences." He used the tip of one boot to lift his victims face.
Dev could only stare into the eyes of the boy he'd loved for three years. His body wasn't responding, but he could feel the tugging and stretching of the spell as it transformed into something different. His ears became thin and long, his body shrinking to the size of a cat, his body hair shifting from brown to a deep black. But the worst was that his clothes had morphed too. His shirt disappearing entirely while his pants bunched up around his crotch and inflated into something soft, but unwanted. Dev wanted to scream at him to stop this.
After what felt like hours, the light from his wand dimmed and he could no longer feel his body changing. Caleb gave him a little push toward the window and pulled back the curtain for him to see. In the reflection he could make out whiskers, tall black ears, a long tail.
"Mrowr" He utters shakily. His new legs wobble and fold underneath him. He can finally see the large diaper wrapped snuggly around his waist.
Two strong arms wrap around his chest and lift him high to curl against Caleb's chest. The witch strokes his new familiars fuzzy head. "What a good kitten you make, my dear."