"Thanks Hermione, I don't know what I'd do without you." Lily embraced her potions apprentice tightly, not noticing the blush on the younger witch's face. "I hope the boys won't be too put out that I'm not here, but if I don't jump on this deal I won't be able to get Chimera Tail carapace for a year."
With a quick kiss to her cheek and a muffled 'pop!' Hermione found herself alone in the Lily Potter's private study. After a few moments feeling entirely lost, she suddenly came to a realisation upon finding a bright red hair on her blouse.
Raking through her magically expanded Gladstone bag, Hermione triumphantly produced a vial, which when unstoppered, and with the hair added, turned a bright red. She poured out half the potion into a glass, stoppering the vial and stuffing it in an expanded pocket. One gulp and a few mildly painful moments later and there stood Lily Potter in all her redheaded glory. Hermione was suddenly aware of the differences in their build as her jeans popped open at the front and her blouse strained, forcing her to unbutton both the top and bottom thirds. She set her watch for a one-hour alarm.
Fortunately for Hermione, acting skills hadn't been necessary for her masquerade. It had turned into quite the little misadventure, where her skills at choking on James Potter's fat cock and taking Harry to the hilt in her needy pussy were the ones most tested.
She desperately sucked James's manhood as deep as she could, swallowing him down her throat. Her careful rhythm was rendered useless as her dripping pussy was pounded by Harry, forcing his father's cock deeper down his best friend's throat every time he bottomed out in her cunt. James grunted his pleasure and, winding the red mane around his hand, reciprocated his son's thrusts into her, eagerly spitroasting their willing fucktoy.
It was just as an hour passed since Hermione had taken her dose of Polyjuice, that James wrenched his cock out of her throat, jacking himself off, spurting a torrent of cum over his wife's features, giving her face a thick glaze of his seed. Moments later her pussy was equally coated with a hot flood of jizz as Harry stuffed himself in her to the hilt and unleashed his load.
Before she could scramble for the next dose of the Polyjuice, Hermione had James feeding his cock back into her mouth, and begin slowly fucking her mouth. Hermione's body convulsed as her dosage ran out, the magic of the Polyjuice seeking to return to her natural form, but her own magic and body resisted. 'Lily' gave James a nervous look around his cock, only for a soft 'pop!' to announce the arrival of the real Lily. The four exchanged looks of confusion, lust and guilt, only for Hermione's slim watch to ring out the hour alarm, twenty seconds too late.
"Oh Hermione. Polyjuice?" Lily asked, receiving a hesitant nod. "You know there's only one reason for the body refusing to revert... someone's been very naughty and got herself knocked up. You're me... for nine months." she stifled a laugh. "I hadn't thought you had such naughtiness in you... as well as both my boys' cocks. Have you enjoyed having all your holes filled?"
"We haven't had all of them, yet." Harry piped up.
"Well we should fix that." the real redhead decided, pushing James out of Hermione's mouth and onto the sofa.
He quickly got the idea and soon had the facialized Lily-lookalike straddling his lap, his thick girth lodged deep in her asshole, stretching it wide.
"And me?" Harry asked his mum stripped off.
"I think you know." Lily laughed, bending over facing her husband and apprentice fucktoy, shaking her butt at Harry. "Come fuck Mummy's arse."
She buried her face in Hermione's pussy, her tongue diving into her folds and slurping at her doppelganger's stretched asshole, dipping to taste her husband's dick as it drove in and out of Hermione's sphincter. Soon, Lily felt her own ass stretching around her son's fat cock, the anal foursome settling into comfortable debauchery as both Lilys were buttfucked, stretched and filled with cockmeat.