I've stumbled upon this image of a narrow angle, coffee cup and the mathematical symbol of pi.
I get its reference to acute and pie, meaning a cutie pie.
But what on Earth is the coffee cup supposed to bring to the table?
In one of the comments from the link provided, you'd see, "acute tea pie". So, it isn't necessarily a cup of coffee. A cup of tea, it is. Hence, 'A cutie pie'.