Now, this can be taken either way. You have them just as friends (in secret) or mortal enemies, inwhich fans love the interaction, but you also have them as a pairing.
Which brings me to the point...
I LOVE THIS PAIRING AND
I AM PERFECTLY FINE WITH YAOI/YURI/THE LIKE. SHUT UP.
Batman and Joker are c/ DC Comics
Wallpaper c/ me
I may do more wallpapers, either on request or at leisure, depends on mah mood and if people like/want them of course. <3