This is why you can't have nice things and generally why everyone becomes a douche to each other in a competitive multiplayer experience.
You should have no sympathy towards the enemy. From the time you join the game to the time it ends you are their sworn enemy as they are yours. There is no reason why you should cease your rampant onslaught against your foe if you are currently dominating. Press the attack and slay thy enemy in the name of the team color. Depending on your role~ (mainly for adc's) remember: walk softly and carry a big gun.
all in all... just have the mindset of a spacemarine.
cleanse. purge. KILL!