Air accumulating inside the vagina eventually escapes. That brief moment when it slips out with a sound, rubbing against the vaginal walls—the "vaginal fart"—is an extremely embarrassing event for women. Both the vagina and anus are made of mucous membrane, and the sounds they produce are quite similar. At such times, women frantically exclaim, "No! It's not a fart!" Their flustered attempts to deny it only heighten the humiliation, allowing for a thorough observation of their deeply embarrassed state.