Is it wrong to play a game with your tank's life?

[Foxkid]

Lately because of how comfortable I am being a healer in dungeons (only dungeons, raids not so much cause succor doesn't cut it for heavy aoe healing without ET), I've taken to being a little silly and playing what I call the "Tank Game" or the "HP Game" with my tanks where I basically just dps while doing as little healing as possible before I feel I need to step in to prevent his/her death and out of control aggro.

If I can get them as low as possible without them hitting LD/Holm/HG and bring them up back up for the sake of doing so, I count "points" for how low I could get them (current lowest score was around 83 iirc before throwing a magic card his way to put him back to half again).

But I do this in my "technical" downtime because I know the dungeons well enough and after gauging their defense after the first pull, but is it wrong that I do this despite never failing it yet just to spice up my time in the run or is it a habit I need to cut short?

(Also, I let them know beforehand that I may or may not play it with them rather than surprise them with only Eos keeping them from bleeding too much while contributing dots to the pulls.)

Although I do end up genuinely surprised when some of them actually make do the majority of the dungeon with only Eos (sans Fey Union) keeping them afloat and give them the proper respects for doing so.