When Xander got home he looked exhausted, but he perked right up when he saw the coffee vials on the table. He hugged Mary excitedly. "Thanks for doing this with me." He picked up the slow burn vial first. "What's this?" Mary explained what it was supposed to do and that she thought maybe she'd be more comfortable if they took it slow. "That sounds like a great idea! Then we can make a whole weekend of it."
Mary made dinner and Xander picked out a movie and they ate and sat down on the couch. Mary drank the slow burn vial first, then handed the self-filling tube to Xander. "Wow, Neat trick." Mary commented. Xander took his swig and commented on how the liquid was flavorless. Next, Mary picked up the wolf vial and squinted as she took her swig. Then handed it off to Xander. They cuddled together on the couch and watched their movie while waiting for the ten hour process to start showing signs of working.
Mary looked at the slow burn instructions again, there was another fold in the paper she hadn't noticed before. She folded it open.
"Warning: Slow burn changes happen entirely at random, some inconveniences may occur."
"Oh." Mary faltered.
Xander put his hands on her shoulders. "It'll be okay." He promised. "Say your hands turn into paws first, well if you need hands, I'll be your hands."
Mary nodded, already feeling a bit of excitement about the night.
The couple barely noticed their first change, the only controlled change that happens by design. Their pheromones were changing to attract someone of a more canine persuasion. Mary and Xander barely noticed and both shrugged off the slight sense of arousal as a reaction to just being around each other.