Batman is looking for a fu**-buddy but he actually got feelings already which he is not aware of yet since he doesn't know much about feelings
And Joker is sincere with all his feelings and know what he is feeling at the moment is love as we all know
That's why they are not equally feeling rn(I think)
I ship
(KandaxAllen
DokjaxJonghyuk
SasukexNaruto
MadaraxHashirama
GintokixHijikata
Mu QingxFeng Xin
Vanoé
Kagehina
KarmaxNagisa
Sherliam
Renga
Satsugu
Soukoku)
the canon alrdy but impossible ones 
