You shouldn't take advantage of someone's generosity.
Ricky and Mark are about to order dinner at a restaurant, and Ricky offers to pay for the food.
Ricky wants to eat food.
Ricky thanks Mark, and offers to pay for drinks and deserts.
Ricky orders over half of the items on the menu.
Mark's friendship with Ricky deepens.
Mark's account goes under, and he's forced to pay overdraft fees.