Busty Girls and Sacred Mushrooms

I'm a mining engineer. I work with a girl, Sherry, who has the most amazingly big breasts. She hates me.
I've been sent to check out a mine in South America, and they've sent Sherry along to help.
We can't get anything done because it's the festival of their saint and his big-breasted girlfriend.
She looks a lot like Sherry, and people keep giving both of us the mushrooms that grow in the nearby caves. At first they were great because they made her insatiably horny, but suddenly her breasts are getting a lot bigger. I like that, but when the locals realize we're not really saints we're going to have to run for it, and with her huge breasts Sherry's not really good at running anymore.