"Alright, it says that I need to take one teaspoon of the powder and then I'll be good to go," Katie put the box down on the counter and looked through the drawers until she found an assortment of silverware. Once she found a teaspoon she dipped it into the box and scooped out some of the powder.
Tiff could smell it from where she stood, pungent and bitter. She wrinkled her nose in disgust as Katie held her nose and ate the powder. She didn't want to eat something like that, but if Katie would play with her afterward or give her a belly rub it would be worth it.
The changes were slow at first, but accelerated rapidly, Katie's belly and breasts shrank down until they were normal again. This made Tiff so happy that she clapped her hands and wagged her tail frantically as she ran over to her friend and began to lick her face.
Katie pushed her away, rubbing her belly and breasts, a look of relief on her face, "You did it Tiff! Now to see if it works for you."
"Then can we play?" As she spoke she became aware of a very intriguing smell coming from Katie. It filled her with strange sensations and desires.
The slick, red point of her dog cock beginning to peek from its sheath she sniffed at her friend. Something had changed about the quality of Katie's sweat, making Tiff unsure of what she wanted to do to her friend.
Crouching down with he dog body she bent her human torso so that she could sniff at Katie's crotch. In response Katie pushed her away, but it was too late. Tiff had realized that she was in heat and found herself overwhelmed by the desires of a male dog.
"Tiff, what are you doing?" Katie's face was flushed with anger or something else.
The sound of anger in Katie's voice brought Tiff back to her senses, though her dog cock was by now sticking at least five inches out of its sheath, "You smell so nice Katie. It's making me feel all funny."
Gritting her teeth in frustration she spoke, "I know. That stuff made me so horny that I can hardly control myself."
Tiff watched with a bemused expression as Katie's hand went between her legs. By the looks of it Katie wanted to mate as badly as she did and the smell was driving her absolutely wild. Katie was in heat and since Tiff was more or less a male dog in terms of reproductive organs her instinct was to mate, "Katie what do we do?"
"I don't know," as she said this her hand went under her skirt and she removed her panties to have better access to her pussy as she fingered herself.
That was the end of it for Tiff, she turned Katie around, put her front paws on her shoulders to force her to the ground and mounted her. Seeking entrance, Tiff roughly plunged her dog cock into Katie's pussy eliciting a moan of pleasure from her.
Tiff panted as she thrust into her friend in a pure animal frenzy of lust. It felt so good to pull her slick red cock in and out of her friend that she found herself making animal noises of lust, growling and panting heavily as her hips bucked and thrust so send her in deeper. Her only desire was to mate with the female beneath her and make her bear her pups.
"Harder Tiff! Harder!" Katie begged her friend to satisfy her need.
Eager to comply, Tiff thrust as hard as she could and buried the massive knot at the base of her dog cock into Katie's pussy, letting out a howl as she climaxed. Katie climaxed seconds later, the muscles of her pussy clamping down on Tiff's dog cock.
They were both panting heavily, but Katie was able to speak first, "Tiff, I want to get up."
Tiff tried to get off, but found herself stuck, her know still buried deep in Katie's pussy, "Let go of me."
Katie tried to pull away and felt pain as she did, "Oh no! We're stuck!"
Frightened Tiff tried to pull away again, resulting in a scream of pain from Katie.
"We'll just have to wait for the swelling to go down, this happens from time to time with dogs I think."
"I'm sorry," Tiff tired to tuck her tail between her legs, "I just wanted to mate with you so badly I couldn't help it. You're a good mate though, you made it feel so nice."