This occurs when a male collects a large quantity of his own ejaculate in one large container (the Mary Poppins Bag). A common use of the Mary Poppins Bag is to be tossed into an unexpecting female during their gynecology appointment - exploding on impact.
Erik: (casually) Yo I just gave Lindsay my fat 'Mary Poppins Bag' on Wednesday.
John: (disgusted) You are actually a disgusting human being... (Curious) Did you film it?
John: (disgusted) You are actually a disgusting human being... (Curious) Did you film it?
by 123allthekidsbulliedme March 5, 2019
Get the Mary Poppins Bagmug. A fanny which appears smaller on the outside than the inside. A very perceiving growler. A very spacious vagina.
by Barry Shaazaaam November 4, 2010
Get the Fanny like Mary Poppins' bagmug. by Chilly Beef March 13, 2019
Get the Mary Poppins's Carpet Bagmug.