What if everyone in Gotham knows that Bruce Wayne has one biological child…
But none of them knows who is?
See, each of his five children acts and looks so much like Bruce that they can’t figure out which one it is. Most swear it’s Cass. She’s the one whose origin they know the least about, plus she acts the most like their father, so the majority of the population assume it’s Cass. Others think it’s Tim, since no billionaire would give his very important company to his kid unless he were his actual child. But a lot of people also suspect that Jason is the product of one drunken night between Bruce Wayne and some random woman who died and left him Jason to take care of, which would explain why Bruce adopted some random street rat without warning. Though questions often circulate about whether Dick Grayson was actually the son of a pair of acrobats, or if it was all a ploy to hide his true origin, which was a scandalous love affair that occurred between Bruce Wayne and Marie Grayson during a trip to see the circus.
Nobody suspects Damian, though. The Bruce Wayne that Gotham knows and loves is a rich playboy who likes picking up ladies and going to fancy parties. Damian Wayne is too grumpy and angry to possibly be the biological son of that guy, right?