Not everyone studies in the library.
Most people don't think of the library as a sexy place. But they'd probably be singing a different tune if they knew what Isabella was doing in there. She starts off studying so she can get good grades. But it always ends with her fingering her slit between the aisles. "It takes every bit of strength inside of me to not moan out loud."
Why the library? Why doesn't Isabella just cum in her bedroom?
Isabella must know that there's a good chance she'll get caught masturbating in the library. "This is high school. Everyone is too busy being cool to spend their free time in the library! So I take advantage of the solitude and get myself off."
What do you think of when you're fingering yourself amongst all those books?
"I think about boys and especially about girls. What usually happens is that I'll try to keep my mind on studying, but it wanders. I've already memorized where all the human growth and development books are so I'll go over there and pull one out so I can look at pictures of naked body parts. I'll look at the pictures of pussies and dicks and get wet thinking of what it would be like to lick them.