"XXY" (story idea, a new giantess and futanari story) (Patreon)

Here's a new idea that popped in my mind, this is roughly the plot:
(NOTE: all characters in the story are over 18. There are strong sexual themes, fornication, fan service, nudity and some profanity. Not violence at this stage of the story.)

PLOT:

A weird virus that hits only male humans.
Effects can vary, but mostly it's either shrinking gradually, reaching random sizes until the body eventually fights it off, OR total gender-bender, leaving only male genitals but changing everything else, including one's scent. There is no cure for this yet and it seems permanent.  Daddy, who lives with his 18 yo daughter since her mother left years ago, is a victim to the shrinking.
His daughter Olivia needs to go to places and can't babysit him all the time. There's the possibility he'll suddenly shrink and she can't come home after drinking with friends only to find out she crushed him like a bug the morning after, right?  So "Ashley" comes in. "He" was her best friend (who secretly wanted to be a woman and had a crush on Olivia's dad) and when he got the virus he became a gorgeous 18 yo hottie who offered to look after Daddy while Olivia is out. 

The story begins when Olivia leaves and Daddy starts making conversation with the 'girl' on the couch.