You shouldn't tell someone how to parent.
Tony is walking down the street when he sees Al spanking his son for misbehaving.
Tony wants to express his displeasure at the spanking.
Tony sighs loudly so that Al can hear him and shakes his head as he walks past.
Tony tells Al that he doesn't know how to be a good dad and that spanking is wrong.
Al sees that Tony is miffed about something but can't be sure why and goes back to talking to his son.
Al is annoyed as Tony doesn't even know the context and is inserting himself into his private situation.