It is uncouth to fart in the presence of others.
Richard watches his little sister start crying when his mom doesn't order desert at a restaurant.
Richard wants to make his little sister smile.
Richard folds a napkin into a small bird to get his sister's attention.
Richard stands up, puffs out his chest, and makes loud farting noises.
His sister learns how to make things out of paper from her brother.
Richard's actions embarrasses his sister, and she hides behind her mother.