You went to a convenience store to buy some food because you're hungry. When you finished picking your food, you went to the counter to purchase the things you'll buy

But, you're inadequate 5 more dollars and you panicked because you thought your money would fit in the amount of your food

Suddenly, a guy noticed your problem so he went to the cashier and said "I'll pay for her food" He handed his card and it was a success, he walked out of the store and you followed him to thank him