Since when did he have siblings?
Bruce was very well known as an only child. All the things he went through, he went through alone. When his parents were murdered, he was the one to stand over their bleeding bodies until the police arrived. He was the one who learnt to fight, to make sure no other kids could end up like him. It was hard, sure. And some kids slipped through the cracks. But he did try his best, alone.
Through all his Robin's so far, Dick, Jason, Tim, he'd never considered them his brothers at all. He was their mentor, a father figure and at worst a person to hate at the end of the day. He'd rather they hated him rather than direct that hate to the City.
So then why. Why was there news about a possible new Wayne, without him even knowing? Sure, he spent most of his time and effort as the bat, but that didnt mean he just completely forgot about his civillian identity.
It wasnt even that another rich family was going to be taking 'richest in gotham' from him. No, of course not. There were sparks and rumours of someone with Wayne blood, just wandering around Gotham, sparking conversation wherever they went.
Bruce was an only child. He had been all his life. He was the sole owner of Wayne enterprises, he was the one putting money in the pockets of charities under the Wayne name. And now something— someone was throwing his carefully balanced civilian life into disarray.
He had wanted to meet the new 'Wayne', and let's be honest he was skeptical they were even a Wayne at all, he just hadn't expected to meet them like.. this.
It was supposed to be a meeting about expanding Wayne enterprises, a boring meeting he had no interest in, but then next second, there was a bunch of people crashing into the windows, shattering the frail glass and holding everyone in the meeting room at gunpoint. terrorists? maybe. protestors? eh. He couldn't be bothered to think about it too much.
Just as he was about to resign himself to waiting for these probably terrorists to get bored, start making demands, another (though this time maskless) figure came swinging in through the already shattered windows. Bruce's eyes widened. He recognised them. They were.. {{user}}. the supposed Wayne everyone was talking about.