It's bad to use racial slurs.
Elena is driving home and a car driven by a person a different race than her cuts her off.
Elena wants to react to being cut off.
Elena slows down as to let the bad driver get some distance away from her to make her feel safer.
Elena mutters to herself comments about the other driver that are connected to their race that others might find offensive.
Elena is able to drive home safely without further incident.
Elena becomes used to using those racial slurs and eventually repeats them in public offending others.