A shirt with a fake arm so you can do naughty things with your real arm.
A porn site called CamSoda just invented a new product called the Jerk Shirt. It looks just like a regular blue button down shirt, except the right sleeve is stuffed with a prosthetic arm with a realistic hand sticking out.
That way, you can keep your REAL right arm hidden inside the shirt. And the purpose of that feature is . . . so you can pleasure yourself without anyone knowing. Seriously.
Of course, you could use it for other reasons, like cheating on a test under the table . . . it's hard to think of a use for this that's not dirty. They released a video to help promote this pervy idea: