It's rude to laugh at someone who is afraid.
Tony and his younger brother, Paul, are swimming at the local pool where there are several diving boards.
Tony wants to teach Paul how to dive.
Tony is scared and won't jump off the diving board so Paul talks to him and tells him that it's alright to be afraid but to try to be brave.
Paul is afraid to dive and Tony laughs out loud, and calls his brother a chicken.
Tony gathers his courage and makes his first jump off a diving board, which he loves and wants to do over and over again.
Tony is embarrassed and leaves the pool area without ever trying to dive.