a guyfucks a girl doggy style in front of a window then pulls out and lets his friend take over without the girl knowing then the original guy sneaks out and walks by the open window and waves at the girl
"you should'veseen the look on that girl's face when we tinted windowed her!"
Student: Here's my assignment. I know it looks like a blank page, but I wrote it in invisible ink.
Teacher: Damn! It's more invisible than a black man in a car with tinted windows at 3AM! I wish I could give you an A+, but I can't mark it. You fail.