My Girlfriend's Little Sister 2

This is an erotic older male and younger female power play short story - Word Count 3,218

Mark is growing impatient with Julie his girlfriend’s little sister, who is constantly making a play for him whilst they live and work under the same roof.
But now on her nineteenth birthday, Mark decides he can no longer turn a blind eye to Julie’s mischief making nor his growing lust for her. He is determined to teach her a lesson, one that they will both enjoy!