When i am in Trial or Raid on a tank and the other tank does not say or indicate if he wants to be MT or not in any way. So i pop tank stance and run in. Other tank also pops tanks stance and does his damnedest to pull off aggro from me, and when he does, he somehow stands behind the boss, so the boss turns towards him and that's usually when shit hits the fan.
Do you want to tank? Be my guest, i'll take being not squishy blue dps any day over these aggro wars between tanks, but, please, say so before the fight starts..