[No prank is a boon, honestly. They had spent days in the diner, surrounded by humans (and monsters they were not happy with but also had to Consciously Decide to not kill), with little to do and less to eat. Trying to coast along on little five-minute snatches of resting their eyes because they did not trust a single person in there enough to actually sleep.
They, frankly, really really needed almost a full week to sleep it off, restore their fried nerves, and just. Not be around people. Except Frisk, I guess. Because they live there too.]
[And that much probably shows in their response. No prank either, and they're right back to being sharp.]
[Sans has seen monster dust enough times that he's not fooled, but it's still mildly unsettling to see. He just sort of sighs, nudges it aside with his slipper and succeeds in getting flour all over his slippers. Well it's not the first time he's walked through powdery substances hahaha...]
[But whatever. Wonderland will clean it up on its own.]
[There's no answer. Seems the prank war is truly over.]
4/24, late, stuck to the door knob
[No prank yet since he forgot and also he's not sure if that's continuing.]
4/25, late morning, they literally nailed this to the door
They, frankly, really really needed almost a full week to sleep it off, restore their fried nerves, and just. Not be around people. Except Frisk, I guess. Because they live there too.]
[And that much probably shows in their response. No prank either, and they're right back to being sharp.]
4/25, night
[Oh yeah real friendly. They're great friends. BFFs. Man, that's hilarious.]
4/26, bright and early
[Don't look now but I think somebody's salty]
4/26, night
[He will literally bet money that Chara is going to "de-face" this note the moment they see it.]
4/26, almost immediately
4/26, shortly thereafter
[There's no answering post-it note, but there is a small pile of ashes left in front of their door.]
4/26, RIP prank war
There's a small pile of dust left in front of his door. May as well return the favour.
It's just flour. They never thought to keep Undyne's dust during That Fun and Wonderful Emotion Event. But how could they resist?]
4/26 a flight of angels sing thee to thy rest
[But whatever. Wonderland will clean it up on its own.]
[There's no answer. Seems the prank war is truly over.]