Penelope and Heather get promoted.

Your wife becomes the greatest new star of the porn industry for about five years. Performing under the stage name B.J. Zero, Heather makes a name for herself as huge breasted bisexual nympho specialising in interracial porn.

Ms. K takes her on as a side project. Although it escapes everyone's notice, watching the pornographic films starring B.J. Zero causes some major changes to Western populations - white guys watch her films and, six months later, mysteriously find their dicks shrinking in size, along with a decrease in sexual prowess to boot. Meanwhile, non-whites enjoying her films get the opposite effect; bigger length and girth, increased stamina and more virile cumshots. No one connects these trends with the...odd porno of B.J. Zero, instead believing chemical exposure to be the cause.
Incidentally, Heather's White male co-stars eventually retire in disgrace, nine months after doing their first scenes with the busty blonde oral queen. They are no longer capable of lasting long enough to finish a scene adequately, and their newly shrunken dicks aren't long enough, either.

Four weeks after B.J. Zero's last scene in porn, Ms. K promotes Heather and Penelope to a higher position in the Mandingo Society; her understudies in magic.
Their first tests are recruiting new male members into the Society. The following summer, Connor brings home white friends from college to meet his family and neighbours. Every time, your wife or Penelope gets them alone, to "discuss things". They think the hot busty MILFs want them for a fuck...but wake up the next morning with no memory of the previous day...or of having a dick bigger than the twig they got now.

Ten years after your disappearance, Heather invites over Rudy, an young white man living in the neighbourhood, promising him a gift to celebrate just turning 18-years old.
She reveals to him a video of his girlfriend getting fucked by Connor and his huge cock.
Then a video of his sister getting fucked by hung non-white friends of Connor.
Then a video of his mother having a threesome with Simon and Penelope, licking pussy and sucking enormous dick.
Lastly, a video of his father trying to cheat with Ms. K but is thrown out when the sexy black woman pulls down his pants and finds a micropenis.

Finishing him off, Heather immobilises Rudy with magic, before taking off his pants and measuring his dick. 8-inches...but that doesn't last long. Rudy is passed out by the time Heather has completed the ritual and got his weiner down to 2-inches hard.

Later that day, the newest member of the Mandingo Society, a Korean boy named Victor, is visited by Heather, who initiates him properly by growing his penis to studly proportions.

Victor loses his virginity testing out his gigantic cock in the steamy pussy and sensual mouth of B.J. Zero. Victor's king-sized willy leaves a marvellous cream pie in her pussy, for Penelope to suck out later when the two apprentices meet later for their daily sixty-nine.

25 years from now, Americans will re-name the micropenis condition to Chronic Caucasian Penile Underdevelopment. Ms. K shares her life extension and de-aging rituals with Heather...but hasn't yet revealed that you're powering her current youthfulness.