I know, I KNOW, Bruce grew up in the rich part of Gotham, I AM AWARE. I know that man has a posh ass rich boy accent. BUT, HEAR ME OUT
Bruce, who spent a good amount of his teen years sneaking out into the city and making friends w street kids. And they pick up on him being a rich boy reaaaaaal fast. Some of ‘em use it against him. Trick him, or at least try, to get money out of him, but some of them don’t really give a shit. Hell, maybe some of them recognize him as thee Bruce Wayne, so they feel a little bad. Can understand that he’s seeking friends and companionship. So they teach him how to hide the posh rich boy accent so that the kind of kids who’d take advantage of him don’t catch on that he’s not really one of them. And Bruce being Bruce, he doesn’t do anything half assed. In less than a week, he sounds as natural as any other street kid, picking up slang and grammar like that’s how he’s always spoken
Now cut to Bruce as an adult, and he overhears Jason and Duke in a nonsensical argument. Neither of them are truly mad, but they’re defending their side like it’s life or death, meanwhile Dick, Tim, Cass, and Damian are watching from the sidelines in utter awe and befuddlement
Tim, “That’s what we’re trying to figure out. But none of us can understand a word they’re saying.”
Bruce, “…but they’re speaking English?”
Dick, turning to look at Bruce, “You…call that English?”
Bruce, “Yeah? What else would they be speaking?”
Cass, “It sounds like gibberish.”
Bruce, frowning, “It’s a Jersey accent.”
Jason and Duke’s argument gets louder and it sounds like it’s about to turn violent, so Bruce cuts Damian off and turns to both boys before he starts yelling at them too, voice thick w an accent he hasn’t used since he was a kid, leaving everyone in the room to stare at him with wide eyes
Dick, “What…was that? Since when did you sound like that?!”
Duke, “WHY DO YOU SOUND LIKE ME?!”
Bruce, “I’m gonna go now.”
Jason, “Hold the fuck up! Explain yourself, Bruce! BRUCE!”
And that’s how the kids find out about some of Bruce’s dad lore, including the fact that he used to smoke on top of rooftops and get into street fights, and even if he’s a billionaire, he is absolutely still Gotham born and bred down to his bones