A few minutes into licking at Mistress's folds she is nearing orgasm, but then the door flies open! It's Mike! You knew Mike, somehow. Your memory wasn't exactly clear, but Mike was a friendly human and you wag your tail at seeing him.
"No no no I'm too late! You fucking bitch!" Screams Mike in a rage. He takes a threatening step towards your mistress, and you spring up, growling. Friend human or not, no one threatened your mistress.
Brooke laughed. "I don't know how you found out about it, Mike, but you are definitely to late. Your friend here is my wonderful obedient servant now, and he's very strong too, strong enough to make short work of you. Sic em, boy!" she says.
Mike yells at you to snap out of it, but it's no use as you leap at him. You knock him to the ground and your teeth move for his neck. "Wait!" cries Brooke. "We don't want him DEAD. I want another doggy." You hold back your teeth, but keep Mike pinned under your weight.
"Fucking psycho bitch!" screams Mike, causing you to growl at him.
"The only bitch here will be you, Mike." says Brooke, "But I'm sure once your friend buries his bone in you you'll fall in love with the feeling."
"Noooooo!" cries Mike as your Mistress snaps the collar around his neck. Then she sits on his legs and starts undoing his pants. He fights, but he can barely resist the compulsions of the collar, let alone your greater strength. It doesn't take long before he's sporting floppy ears and a muzzle just like you. You don't understand how this is happening, but you wag your tail at the thought of having a new friend to play with.
"You're almost there, Mikey dear." says Brooke. "But your change will of course be a little different. You'll be cumming out your manhood as well as your humanity. Here that, boy?" she says, now addressing you, "A nice bitch for you to fuck."
This time you understand, and your tail wags all the faster as your cock begins to reemerge from its sheathe. But then you see Mike grin. Mistress doesn't notice. Has he given in to the change? No, something seems wrong, and you let out a small concerned growl, but it's too late to do anything as Mike cums. As the transformation completes you watch his cock shrivel up inside of him, and two human-like breasts form above a row of dog-like teets, but only for a brief moment. You feel your Mistress grab your cock to guide it into the new bitch's pussy, but as fast as her tits had appeared they vanished again, and his cock reemerged. Furthermore, he was turning back into a human.
"What the fuck?" Said Brooke.
Mike laughed. "Did you think I wouldn't come prepared to deal with you, bitch? I bought a counter-curse before coming over here, designed to reverse any of your magic back upon you at the moment of finalization."
"Noooooooo!" Cried out Brooke, but she scarcely had a moment to do anything about it before a rapid change overtook her and she was a full dog-girl. She tried to growl at Mike but then her orgasm overtook her as well, and she fell to the ground whimpering in pleasure.
Suddenly, you didn't feel submissive to Brooke anymore, in fact, you remembered being human! That...that bitch! You got off of Mike and growling made your way over to Brooke.
"Hey man, make love, not war." said Mike with a wink at you. That indeed did sound like a plan. You'd fuck the bitch raw for this. Her eyes widened in fear, but when Mike commanded "Stay, girl. Submit, and prepare to be bred." something came over her and soon she was on all fours with her ass in the air for you. Your heightened sense could easily smell her still twitching pussy. You smiled as you made your way over to her.
"I'm sorry, man." said Mike, "But I don't think there is a way to turn you back. But I promise I'll take good care of you."
But as you bury your bone in your bitch, you hardly care.