Your nose senses something that doesn't belong and wants to rid the body of it.
It's a popular running gag usually referencing the nosebleeding person has seen or thought dirty things.
Gag yourself, tickle the inside of your nose (it will make you feel like you have to sneeze. If you fight it, you'll cry). And unless you're preparing to be a professional actor/actress, crying on demand is a hurtful, deceiving thing to do.
If you sneeze on a Tuesday, you will kiss a stranger. The whole rhyme goes: If you sneeze on Monday, you sneeze for danger; Sneeze on a Tuesday, kiss a stranger; Sneeze on a Wednesday, sneeze for a letter; Sneeze on a Thursday, something better; Sneeze on a Friday, sneeze for sorrow; Sneeze on a Saturday, see your sweetheart to-morrow.
gag
It stands for "Gag Box"
Because when you sneeze the sound you make is "SNEEZE!" ^No, it really isn't. I've not heard one person say "SNEEZE" when they sneeze, ever in my life. I've heard people say "Achoo", "Atishoo" and other ones, but never "SNEEZE".
The term gag factor refers to the gag reflexes. For example, a baby has very sensitive gag reflexes so even small amounts of food may cause the baby to gag.
sleeve
Gag
probably Over The Nose gag..
Sharks have no gag reflex.
It is poo