"Easy big boy. You don't want to take me before you're ready." Janet smiles big and you can see her sharp new canine teeth. You also notice that her ears have grown larger and are now pointed. As you watch her, her hair begins to retract into her head as her ears move up to the top. As they reach the right place for a dog, her ears flop over. Janet's face now resembles that of a yellow lab. If her body wasn't still mostly human, you would think that she was just a common dog.
You don't have to wait long. Her body begins a strange quivering. Before you know it, her body looks like a dog's.
"Janet, are you OK?" you say, a little worried.
Janet just looks at you and whimpers. She comes over and nudges your cock. After she did, you look down and realize that your cock has changed. It's now a pointed red rod poking out of a dark furry brown sheath. You catch a glimpse of yourself in the mirror on the other side of the room. You hadn't noticed it until now but you had developed a very short muzzle and your body hair had nearly tripled. As you watch the other changes creep over you, a odd smell drifts to your new nose.
The smell is musty but sweet at the same time. Your mind becomes clouded by the smell until you can't think about anything other than finding the source. You realize that the smell is emanating from your transformed girlfriend's rear.
You get down on your hands and knees and crawl over to her. You stick your nose right in her rear and lick her new pussy. Before you know what you're doing, you mount her and hammer away at her. Soon you can't pull too far away from her and you realized that you are locked to her. You feel the cum welling in your transformed balls. As you release into her, you and Janet howl in unison.