Your brother walks into the room. He is naked. His cock is in a sheath that goes half way up his stomach. His tail is between his legs and he has a collar around his neck. There is a leash being held by someone, you can't tell who though. Your brother walks further in, the thing holding the leash is the booth attendant.
"Sit" she demands. Your brother drops to his knees.
You sit up in bed revealing your naked mostly dog body. "What have you done to him!" you start growling.
"I've tamed him" the booth attendant says.
"You bitch!" You say.
"Watch your mouth. Remember your the one who made him like this" the booth attendant starts grinning. You get off the bed get on your knees and hug your brother. "Max, fuck" the booth attendant says.
As she says that max starts to make out with you. At first your opposed to it, but your still in heat. So as he's making out with you you grab his erect penis and slide it into your soaked sex. He starts thrusting, going deeper into your pussy every time.
Max starts to whine you don't know how but you know that means he's about to cum. You whisper in his ear "I want it all, give it all to me"
Not realizing how far along your changes have come, you let him cum inside you solidifying your changes and his into dogs. There is no longer any human left in your brother
...or you