How to treat the behavior of drinking drinks before paying in supermarkets?

How to treat the behavior of drinking drinks before paying in supermarkets? First of all, according to the actual situation, if this person is really thirsty and needs water too much, it doesn't matter to drink it first. But he must explain clearly.

Second, this behavior violates the rules of the supermarket. If everyone eats first and pays later in the supermarket, then I can't measure how much you eat and drink, so it's not a special case. As long as you violate it, the supermarket can still hold you accountable.

Third, pay first, then drink, which is a kind of respect for the supermarket. Although you drink drinks before paying in the supermarket, you never buy them when you drink them. This thing always belongs to others. You drank the drink without permission. People in the supermarket will definitely be uncomfortable. If you drink after the permission of the staff, then I think it is ok.

Fourth, adults should know how to abide by the rules, set an example, improve their personal cultivation, personal quality and pay the bill in a civilized way. Although there is no express provision in the law, it is not harmful to society. But personally, I think this behavior is very bad. Think again from the supermarket owner's point of view. Thank you.

The picture comes from the internet.