The Joker surprises Batman with the capture of the entire Bat family, with their faces cut off similar to the Joker’s. We’d later learn that it was just a sick joke and Joker never really took out their faces – fortunate for them but unfortunate for the people whose faces the Joker really did cut off.
Joker continues by taunting Batman that the reason he’s never tried to kill the Joker at all is because secretly, he likes playing the game with him.
From – Batman Vol. 2 #17