It's not okay to use the word retarded anymore.
Rich came to his friend Ron's house and noticed that his friend has a brother with cerebral palsy.
Rich wanted to make a comment on Ron's brother.
Rich tells his brother that he should've told him that he had a brother.
Rich tells Ron that he didn't know that he had a retarded brother.
Ron feels good that Rich didn't mention his brother's disability.
Ron feels offended and tells him never to say that word again.