Grab the closest object and smash it over his head.
From Create Your Own Story
You quickly look around to see if there is something you can use as a weapon. You see a stapler on his desk so you grab it and fiercely hammer it into the back of this creep's head. There was a loud crack, followed by an agonizing cry from your target. You're not sure if that sound was from the stapler or his skull. Your answer was quickly answered when you look on in horror as blood begin to gush out of the back of his head. He collapses out of his chair and lies motionless on the ground.
"Oh my gosh!" You frantically hurl the stapler to the ground and drop several steps back. You have wanted to teach the perv a lesson, but not beat him half to death. What do you do now?
Finish what you started. Beat him til he's good and dead.