The Literal Commandment
"You shall not curse God, nor curse a ruler of your people." (Exodus 22:28)
The Hebrew word translated in this verse as curse means "to be slight, swift, or trifling". 1
This verse might be more accurately and literally translated as:
You shall not act towards G-d in a casual or disrespectful way.
When a child acts towards his or her parent in a way that is merely casual (as they might treat a friend or classmate) instead of with respect then they are acting in this manner.