There are times when I'm at the supermarket and I would like to drink one of the store's drinks before I purchase the drink. Or maybe I want to give my kids something in the store so that they stay calm while I do my shopping. I fully plan on purchasing whatever I eat/drink and I see that it's normal for other people to do this.
The question is: Is this permissible? And if not, is there any way I can do this? (e.g. ask an employee if I may start drinking the drink before I buy it? Maybe an individual employee does not have the right to grant me that right?)