A question of ethics (slightly OT)

[bcubed72]

Just wondered where other people draw the line. Poker is a game of misinformation: it pays to convince your opponent you're weak when strong, and vice versa. Along those lines, I have no qualms about misleading an opponent. However, I never lie at a table, not even about folded hands (which almost everyone does). With that setup, here's my dilemma:
Dealt KK, flop set, turn quads. River 7, making K97K7. I make a weak bet, my HU opponent raises, I push. Opponent thinks a LONG time, says, "You don't have a king, do you?" I acknowlege that I don't, misleading (but not, I believe, lying.) If he had a crafty and devious mind, he'd realise I was telling him I had either 0 or 2 Ks.

When he calls (w/ 7s full) and I show, he's spitting mad. I calmly tell him (and am actually backed up by 2 other players) that I told him the literal truth. When I posted this at another site, the reaction ranged from "you're a jerk" to "he had no business asking; feel free to lie outright."

(Here's the OT part.) My school just introduced a policy whereby only water is allowed in the classrooms. This is hard on me with my many early classes and am currently drinking coffee and flouting the regs.

I figure that noone can conclusively tell what's in my spill-proof mug. But if asked, I need a way to mislead without outright lying. I feel responding "I'm drinking water" is a lie, even though coffee is 95% or more water. I think I'm telling the truth, however, if I respond "my mug contains water" (and hope they don't follow that up with "does it contain water EXCLUSIVELY?)"

Just curious where everyone draws the line.