It's rude to tell your father what to do.
Ron is at his parent's house, and sees that the lawn is massively overgrown.
Ron wants the lawn to get cut.
Ron goes into the garage, gets the mower and cuts the grass himself.
Ron tells his father that he needs to cut the lawn, that the neighbors will be upset.
Ron's father is very thankful that his son is taking care of him.
Ron's father is embarrassed that his son called him out.