By the time they got back to the house, Bobby had decided that he wanted to change the dynamic of this relationship with Kaitlin. He wanted her to be aware of the changes, and so he tried wishing for it.
It worked, and after intial shock and surpise at her newfound frailty, she quickly became aroused.
"Oh, Bobby... I never thought I would feel so old", she moaned pressing herself and her softened breasts against his firm body.
Brushing aside her maine of grey, Bobby kissed Kaitlin's wrinkled neck and ran his hands down her sides to her suprisingly soft, but still relatively small waist.
What happens next:
Bobby explores Kaitlin's new body.
In bed, Kaitlin asks to be regressed slightly and takes some of the years for himself.