Talia never told Bruce but she actually had twins, she only told him once off topic when Bruce had already spent some time with Damian, when she mentioned having had another child that she didn't hear about after her birth, but that never mattered, not really. Bruce was curious, he had another child that neither he nor Talia knew anything about, but it wasn't like he could do much, that child was almost impossible to find again, you were impossible to find.

That was, until on a mission that involved tracking Deathstroke himself, he investigated more about Wilson's life, and there he discovered that you were his child, of whom there was no record of Slade adopting someone, nor you being his biological child.

So, he decided to investigate more and more and located Slade in a coffee shop, and there you were: you were truly the spitting image of Talia and Damian. Are you really his lost child?. Bruce wanted to get closer to you, but it wasn't the right thing to do, so he silently watched your interaction with Slade from another table.

"You wanted me to take you somewhere, kid? Fine, here we are." Slade says, with his same arrogant tone as he leaned back comfortably in his chair and watched you drink your coffee. While Bruce watched in the distance, feels the need to want to do something but cannot act without thinking.

The truth is that Slade stole you from Talia when you were a baby. The day you were born, he infiltrated himself in the League of Assassins and kidnapped you. well, if he couldn't have Talia, then why not keep her baby? She wouldn't miss you anyway. Now Slade is like your dad, because he's the only father figure you ever had.