Ganging up in a non-doubles multiplayer game

[Drahmee]

In a three-player game, is it considered against the rules (I don't think so), or in poor taste for my two opponents to talk about not attacking each other so they can focus on me?
It's not a teamwork match, but they are doing it and strategizing. I don't mind being attacked by both, but I prefer they do it each on their own(without discussing it), not as a team.
What would you give them for a rating?

[Frox333]

Game #?

also, generally speaking, it matters how big you are compared to them. I mean if you are bigger than them both combined then its acceptable, otherwise there is really no need for it.

[Drahmee]

Game number #14626993. Now he is talking about avoiding giving me spoils and giving them to another player, and I am no longer the strongest player.

[IcePack]

It's not against the rules, as long as all the discussions are in the open in chat of the game.