Since when was it the Tanks job to explain fights?

[Milmoko_Gemoko]

I dont mind explaing fights, I dont mind a few wipes on peoples first runs (or even if their experienced sometimes) and hell I'm tank but I ask for advice myself on new encounters (i dont like video guides on story events sometimes for fear of spoilers lol) - but it does annoy me when people with better gear then me stand there and expect me to play teacher all the time.
This morning for example Lost City on Roulette - party was 2 lv60s (me and a NIN dps who had better gear then me, I gear checked), 1 lv52-53ish Healer (gear check est.) and a newbie SMN DPS- we get to final boss and it goes:

NIN: "Just burn him down?"
ME: What about doors?
NIN: the SNM can do it
ME: he doesnt know mechanics

We pull we wipe after his masive attack.

Round 2:
NIN: he didnt do the doors
Me: Its his 1st time, he doesnt know mechanics so not his fault
SMN: What do i do?
NIN: You expain it to him (meaning me)
ME: Er no as I Tank I dont to the doors so I dont know what door you open, DPS have always done the doors
*silence*
ME: explains the basic idea
SNM: speaks french (I faceplamn in RL not because he french but because he probably didnt understand me)
ME: NIN your clearly also lv60 so can you please get the doors?
WE Pull

*Mid fight* NIN: I'm meele DPS i cant
ME: so stop DPSing for a second and get the doors

We wipe again, new guy leaves and DRG pops in and manages to open the doors.

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Sorry but the sheer laziness and expecting me to explain something I've never actually handled (never roled DPS for it) and just because I'm Tank - give me a break!
I love Tanking, I dont mind explaing things and tbh I like helping someone clear something first time as it helps progress them and the community, but I'm not defacto strategy guide and I cant do everything - I'm not god lol.