Honour...
Do what you can to win for the team.
Showboating, bro love, throwing a round, and soft play is...
dishonouring your team, especially if the loss comes about because of your actions.
dishonouring your opponent, as they may 'win' when they should have lost, thus you are depriving them of the experience and opportunity to learn from defeat, i.e., you are really saying 'you are not good enough for the full game'.
Also it's a game, expect various levels of boredom and other shenanigans and you should be ok.