The vagina is referred to as Natures Suitcase only in situations of concealing some thing they don't want to be found by a third party, aka the "police". This area can hold an enormous amount and is highly versitile, but like any suitcase, a dog can sniff it out and a warrant is needed to open it.

the art of remembering an arousing occurrence or some porn you watched while masturbating, often handy if you have no porn or your in the shower