Spiderman would drive the Joker crazier by constantly replying to everyhing the Joker says with nothing but "Your mom" comebacks.
The Joker is announcing his plan to release toxic gas on Gotham's water reservoir, and Spidey just says "Your mom had toxic gas"
The Joker is announcing his plan to make everyone at a stadium go BOOM with a great explosion and Spideys says "Your mom's gas goes BOOM"
The Joker has enough and grabs a machine gun to riddle him with bullets and Spidey says that the Joker's mom was riddled with acne scars
The Joker opens his mouth to say something and before he could say a word Spidey has already shouted "YOUR MOM" from the other side of the room.
Eventually the Joker has enough and goes back to Arkham on his own to wait out until things are less retarded, only to find his cell full of "UR MOM" graffiti written with web fluid.
After the Joker is done tearing that up and screaming on top of his lungs about how repeating the same infantile joke ad nauseaum is not funny, a nervous guard comes to his cell to give him a pie.
It's a normal looking pie with nothing out of the ordinary.
"A pie?" says the Joker. "I just arrived here. Who could have sent me a pie?"
"YOUR MOM!" the guard says, as he removes his mask to reveal he was Spiderman all along.
The Joker just watches him webbing away, and once Spidey is gone he still just stands there, holding the pie.
Then the Joker just sighs and splats the pie in his own face
The empty tin falls to the floor and the Joker reads the words "UR MOM" written on it.
A blood vessel ruptures inside of his twitching eye.