Yes, close the window.

You decide if you're going to do this, you might as well do it properly, and so you tiptoe over to the window and grasp it firmly in your hands. You give it a quick tug, but it doesn't budge. Grunting with the effort, you put all your weight on the window until finally with a loud squeak, it slams shut. Suddenly paralysed, silhouetted against the light shining in from the window, you hear a rustling from behind you. She had woken up! You wonder whether you should just come clean, or make up an excuse. The erection still suspended between your legs, and the fact you're not wearing any clothes, might make this difficult...