note: there can be an episode where batman gets a hint that they're where they are and comes on down to try and find them
however
this will be played completely for comedy as batgirl, robin, wonder woman, superman, etc. all totally see Harley and Ivy and all react with "y'all are doing good shit actually, we're going to keep fucking mum even if this means some very silly LOOK-A-THREE-HEADED-MONKEY behavior so we can keep batman from seeing you"