This Saturday tomorrow that 7/11 let you bring whatever cups or anything to the store and fill it with slupees, I am going to bring a big huge bucket that is 3 or 5 gallons, or a water cooler and make it full with slupees, and it's only $1.00.

"Bring Your Own Cup Day"

http://www.businessinsider.com/7-11-bring-your-own-cup-day-2015-4