It's rude to spew body fluids on other people intentionally.
Marcus is on his way home from work, driving a bit faster than he should and gets pulled over for speeding.
Marcus wants to get home quick enough to catch the end of the Celtics game.
Marcus, annoyed at getting pulled over, complies with the officers instructions.
Mark annoyed at the cop for pulling him over spits at him.
The officer lets Marcus off with a warning after a few minutes and Marcus is able to get home in time for the second half of the game.
The cop gets furious and arrests Marcus for assaulting a police officer.