Your best friend fucking your mom into a dog is too much for you to handle and you stumble out the front door. A passing car reminds you that the crotch is torn out of what's left of your pants, and you make for your back yard. Your hands shake as you fumble open your gate. A layer of fur is covering your skin, and your heightened senses can still smell the dogs humping in the entry way. Panic starts to fade and you almost begin to think of a reasonable course of action when you suddenly feel Helen's affections.
Someone had left Helen's door open, and she has gone straight for your doggy cock. You can't find the will to stop her and just hold her head in place. You feel rough patches forming on your palms and fingers as you caress Helen's head. This isn't like your last encounter, you feel calm; your mother and Cal had essentially raped you, but Helen was now offering herself freely. Your pants become slower and more rythmic while images of dogs mounting fill your mind.
You have always got along better with dogs than people, now you were becoming one. Mating with Helen would not likely make a difference either way, so why not. You kneel down and make out as best you can with the bitch's muzzle. Beside your dick, your only other canine traits are your fur and bottom of your nose ending in a cold tip, making you look like a 40's wolfman.
You stop thinking about your appearance, Helen has had enough courtship and has raised her tail to you. Your ultimate decision was made as soon as Helen started lickng your crotch, and you careful guide yourself into her cunt. Something changes within you, and you jackhammer yourself into her, sending out a surprised whelp. She's a large dog, but you manage to hold yourself onto her with your forearms. You feel yourself change as your sweat glands disappear and your physical features change into that of a black labrador retriever. Being completely human again is now impossible, but your only concern is the excited bitch beneath you. The instincts to mate, dominate, and belong to a pack attach themselves to your largly unchanged consciousness.
Your climax arrives after Helen's, at which point you flood her vagina with your seed. Helen is your dog, you and she both know it as you wait for your knot to untie. You've enjoyed being a dog so far, but Cal didn't have the right to turn your family into dogs and you start thinking of ways to get even. You're about ready to untie when...