is this unsportsmanlike behavior?

Are cheaters banned from playing? or can they still play?

so the op is a cheat and asks about sportsmanship? strange fellow.

This is actually too funny to be true, to the point where i think the OP might be trolling :P (but i doubt it)

@#8
Is 1.Nf3 .... 2.g3 cheating because it is not the best opening? Do you really think so or did you just talk without thinking?

Do not missunderstand me, but just ignore the strength of the opponent is not cheating, its often just a mood.

#14
The question wasn't about cheating. It concerned what one would consider to be sportsmanlike behaviour.
Neither did I define suboptimal play. Obviously there is no clear line. Boosting (such as giving away pieces) for instance is against the rules while more subtle examples (such as 1 f3, 2 Kf2, 3 Ke3) just might be considered "ungentlemanly".
Of course no one would consider an opening such as 1 Nf3, 2 g3 to be a mockery.

OP did however clearly state he/she played bad moves intentionally to give the opponent the upper hand. This I am not in favor of.

1.Nf3 .... 2.g3 is a perfectly valid opening, its king's indian.

yeah its fairly obvious when a player uses a completely troll opening and then crushes you into the ground from what is arguably a lost position that the player is using assistance.