Cup to it Grab a big straw and slurp away with this cool deal from 7-Eleven. On Aug.18 and 19, from 11 a.m. to 7 p.m. each day, bring your own cup to the ubiquitous convenience store and fill ‘er up with your favorite Slurpee for just $1.50. Before you start thinking about filling up a bucket, there are rules for “your cup”: It must fit through a 10-inch hole upright, be food-safe clean and watertight.