Don’t mind the blood. He’s a sharp-dressed Prince Clown.
Once, as a joke (of course) J got hold of one of Batsy's capes and tried it on over his suit and started flouncing around pretending to be the broody Dark Knight, (and Batsy is totally NOT Into It™........) but one day Bats realises J kept the cape when he bursts in on him curled up asleep in it. When he asks why J gets flustered and mumbles "'Cause, yknow. It smells like you." And Bats is definitely blushing super hard under the mask (and just wait til he sees J in the cape and NOTHING ELSE)