To excrete an enormous amount of flatuance into the office chair you are sitting on while working. Then let permiate into the fabric and cushion of the chair. When an unexpecting co-worker walks by your cubical you let them pass by and then call them.
When they turn around and walk towards where you are sitting, you slowly get up and gently push the chair over to them and marvel at the disgust on their face.
Do da do, Ahhhhh... "Hey Harry, check this out for a second" (office chair is pushed gently towards Harry as he is walking towards you) (Harry's reply) "NO Dude! Your not right man that fuckin disgusting!" HAHAHAHA that must be your first chair bomb.