In this how-to video, Kipkay shows you how to build a portable stink pen and you need a cheap pen, a bobby pin, and matches. Take apart the pen, save the spring, put the bobby pin through the center of the pen, and bend the edge of the bobby pin. Pull the pin back to fire and create one gross smell. Watch this video pranking tutorial and learn how to build a portable stink pen for practical jokes. Use this as inspiration for one of your April Fools Day pranks!