yelling hateful things after you lost
saying they cheated and pouting
whining cuz you lost and they keep beating you
complaining and getting agrivated just cuz that person wins more then you
not congradlating the person and being mean
not supporting the other person
being a bad team player and hogging the ball or what ever it is you are using for the game
and lastly trying to beat the other person and not realising that its just a game and doesnt matter if u lose as long as u had fun