Before Jenny can kiss her brother, she begins to feel a tingling sensation all over her body. Her breasts grow significantly larger, (HH cups) and become very sensitive, especially around her nipples. Her waist narrows and her hips flare out and her butt swells a bit as well. Her hair darkens a few shades and she shrinks to about 5''2.
Her brother Harry gasps at her transformations and launches himself toward her. She's become a physical manifestation of his ideal girl!
Pushing him on the bed, Jenny lets go of his cock and strips off her too tight clothing. Her pussy, soaking wet, rubs against his leg before she pulls out his cock and pushes him deep inside her. Jenny gasps in relief, and Harry turns her over on all fours, plunging into her from behind. He plays with her enlarged clit and squeezes her breasts with another hand.
Jenny is in ecstasy, the walls of her vagina now as sensitive as the average g-spot. She comes repeatedly, passing out after Harry comes, having experiences her eight orgasm. Quivering, harry pulls her to him and kisses her deeply the transformation making his acceptance if his sister as a lover incredibly fast. When jenny wakes minutes later she finds Harry to be in deep sleep, his hard member throbbing inside her. Finding the sensation blissful, she falls into slumber as well.
"I love you brother..." she mumbles into his pillow.