I’m about to blow chunks!
Say you’re in a busy department store and want to get out as soon as possible. However, the herd of mindless shoppers are blocking your path to freedom and can’t just Mario-jump your way to the door. What you can do is scream that you’re about to vomit. That’ll get everyone’s attention.
Nobody will dare check you for symptoms of food poisoning or something. As soon as someone yells the word “vomit,” they’ll part like the Red Sea. After realizing that you were lying, they’re not going to try to catch you out of fear of getting chunks hurled all over their clothes.