Nikki was lying on her bed, one half clock watching, one half entertaining herself with the toy. It was hard to get into the flow when your best friend was having a noisy shag next door - it was even harder knowing your best friend was about to have the shock of her life, or not as the case may be.
She knew that Jessica's favourite position was the Reverse Cowgirl - heck, she'd walked in on her with Chris enough times - which was perfect to hide the change for as long as possible.
The moans were quickly turning into grunts and panting and the bed squeaking was picking up speed.
She closed her eyes, imagining the change happening right about now - 10 minutes left according to the clock - as Chris pumped her from behind, the sensation growing in her crotch as her clitoris grew, widened and morphed. She imagined the sensation building enough that Jessica would absent-mindedly start fondling herself, unaware of what was happening or why, just that it felt good. She imagined her reaching orgasm with both male and female equipment simultaneously (without the mess), then she imagined her climbing off Chris's penis, completely satisfied and turning to face him.
Chris's face when greeted by the site of his girlfriend with a penis that could match or exceed his own was an amusing development. She also imagined the confusion Jessica would experience, assuming the settings on the program worked...
The thoughts overwhelmed her so much that she hadn't realised that she had filled the pocket pussy. She continued up until the instant the moment was ruined...
"HOLY SHIT! WHAT THE FUCK JESS!", followed by a few words and a loud scream... muffled words were heard, followed by shuffling and bumping, a slamming of a door, steps down the stairs and the front door slamming on its hinges.
Nikki cleaned herself up and opened her door. Wearing just her t-shirt and socks, she leaned her head against Jessica's door and listened.