You free his friend...

You are a guy who has been chosen at random by a Cultist who worships Shubb-Niggurath, the Black Goat of a Thousand Young, to be cursed for a week as a woman. She explains everything to you from how she does this every month to appease her deity to her rules on how you can undo the Curse; the primary task being not getting pregnant and unleashing an eldritch horror into the world like so many before you. See if you can break the curse or fall victim to the unrelenting lust...