Although the chag has ended, please note for the future: on Purim we tend to let our guard down and for good reason; we are happy and relaxed and are in the mode of “achva v’reius”. We allow strangers into our home (groups of bochrim; collectors; etc.) and are not as alert to what is going on as we would normally be.
There are many times when strangers have a license to roam about our homes, i.e., Purim; Sheva B’rochos; L’chaim; Vort; etc. I was at a Sheva B’rochos several years ago where the hostess left her diamond ring on the window ledge above the kitchen sink when she washed for bread and discovered it missing during the meal. There was a house full of people she not know and she let her guard down because of the simcha. Purim is no different.