I remember something my first DM did.
Player: Ok. I’ll open the door.
DM: You’re turning the doorknob?
Player: Wait. Never mind. I’ll search first.
DM: Too late. Which direction do you turn the doorknob?
Player: Sweating. Um… clockwise?
DM: And which hand do you turn the doorknob with?
Player: Ri-… Left.
DM: And do you push or pull the door?
Player: Push…
DM: The door swings open.
The entire table was dead silent for a full 30 seconds. Nothing ever happened. Or if it did, we never made the connection to the door.
That DM was a joker. Lol.
My old DM’s favourite was the good old “you sure about that?”
Now and again they’d ask it as a bluff, so you never knew for sure if they were serious or notIt’s always great when the DM asks the player if they’re sure about that and the player still does the crazy thing, and then gets mad about the consequences.
Played with one murderhobo that attacked 7 town guards in the town square without warning by themselves. The DM asked the player if they were sure ans the player still proceeded. When the guards attacked back and killed the player’s character (all while the rest of the group just watched as this wasn’t the first time dumb shenanigans happened), the player complained. “It’s what my character would have done.” and the DM responded with “it’s what the guards would have done.”
Suffice to say the next session that player had a new character that made slightly smarter decisions.
Ours has been using “Well you feel like you’re hidden”
Where are you keeping your coins?
This one is particularly funny to me since I am the only player in my group that meticulously denotes not only what I have, but where I have it. From the container to the placement of that container. I tend to play liars and sneaky dudes a lot so I have all kinds of hidden compartments in my clothing and even my tools to stash things.
“I take out my portable hole.”
“Where did you have that portable hole?”
“In my bag of holding of course.”
Placing a portable hole inside an extradimensional space created by a bag of holding, handy haversack, or similar item instantly destroys both items and opens a gate to the Astral Plane. The gate originates where the one item was placed inside the other. Any creature within 10 feet of the gate is sucked through it and deposited in a random location on the Astral Plane. The gate then closes. The gate is one-way only and can’t be reopened
https://roll20.net/compendium/dnd5e/Portable Hole#content
As a DM that delights in destruction, that would definitely trigger a new plotline.