It was still dark when Erika realized she had fallen asleep with Melissa nested against her in the large bed. Hours must have passed and there was a storm outside; the thunder was rumbling and she could hear the rain falling on the roof.
The first thing she noticed was the heavy weight of Melissa, who had crawled on top of her body and had been hugging her tightly in her sleep. Her ample bossom was almost pushing into Erika's chin. Melissa's breathing was deep but slightly irregular, and she was moaning softly in her sleep. As Erika tried moving slightly to better breathe, she became aware of a dull pain on her groin.
The canine member was returning, slightly pulsating in its lengthening sheath.
Erika's heart started racing. The goo's effect had faded in her sleep. It had been maybe half a day since she had drank it, and her condition was now returning with full force.
She tried wiggling her hips to disengage from Melissa's sleepy embrace, but it made her canine cock harden and slip out of its shaft. Melissa's breathing became more agitated and Erika laid still, afraid of woking up her friend. She didn't know what to do.
There was no way to explain this to her friend without freaking her out... "Hey Melissa? I accidentally sprayed myself with a weird salve, and now I slowly turn into a horny beast unless I milk the goo from my peepee; and I have all these weird thoughts and urges in my head and dreams..."
In her sleep, Melissa squirmed slightly against Erika, their hips rubbing together. Erika's pyjamas were only an ample t-shirt, and it was riding up more and more until her member sprang free from the constraint. The erection rose slowly and brushed between Melissa's thighs, who was still laying on top of Erika. The more Erika was trying to shift her position under Melissa's weight, the bigger her hard-on was becoming, until it nested itself between Melissa's legs - poking against her friend's pyjamas shorts.
Erika froze and waited, hoping to avoid a catastrophe. Minutes passed but her whole body was tingling. Her canine nipples were pushing out and poking against Melissa's body through their shirts. She could feel her ears and teeth becoming pointier, and fur slowly spreading from her groin and arms. But she could not get away from Melissa, not without waking her up. She was stuck in her friend's embrace.
Melissa squiggled against her once more, and a surge of pre oozed out of Erika's canine wood, smearing lubricant against Melissa's shorts. Erika's balls felt inflated, churning with goo and growing alongside her cock. The sensation was driving her crazy, making her member throb and self-stimulate against her friend - and the larger she was swelling, the tighter her member was squeezed between Melissa's thighs.
Erika was clinging to the bedsheets, unable to keep her penis under control. It was like it had an agenda of its own. She felt appaled by the situation, she didn't want to cause any harm to her friend. She laid helpless as the pointy end of her canine cock was probing against Melissa's mound and ass crack.
The fabric between them was so wet that it stuck to their genitals. Erika could feel every little detail of Melissa's anatomy. Her cock's throbbing intensified, the knot expanding at its maximum against Melissa's barely covered sex, while her balls drew closer to her body.
"N..no!" Erika whimpered between her teeth before clenching her jaws tight.
A heavy burst of cum splattered between Melissa's legs and ass cheeks, drenching her shorts and sipping through. Erika let out a stifled moan as she tried to keep her hips from bucking wildly. A cascade of goo kept on overflowing from her pulsating member, soaking everything while Erika was praying all her heart that the spasms wouldn't wake her friend...