When someone puts their lips up to a vagina and fills it with air as if blowing up a balloon. You can then take the labia betwixt your forefinger and thumb at the top and the bottom of the vaginal opening to control the amount of airflow on the way out. Moving your hands away from each other while still holding the labia will restrict airflow and cause a high-pitched squeal, and bringing them close together will cause a low-pitched almost flatuesque noise. It is not advised to let go of the labia before the vagina has equalized air pressure with the outside atmosphere because there is a risk of the woman flying around the room and injuring herself or others in the process. An advanced knowledge of rocket science is needed to explain this phenomenon.
Did you hear Katie is in the hospital? Aparantly there was a pretty serious accident when she got a salmon balloon from Ben.