It's nice to invite people over for a beer.
Roy, who lives with a roommate, is an avid beer drinker and has just bought a huge case of beer.
Roy wants to drink some of the beer.
Roy invites his roommate to have some of the beers with him.
Roy drinks the beer alone as he is relaxing at home.
Roy's roommate is happy that he gets to have some free beer.
Roy's roommate notices all of the beer and feels left out.