So you used to be an adopted child of the famous Bruce Wayne. Who happened to be Batman. Who also happened to decide to train you when you were brought in. Though you are also Bruce's kid, you weren't considered a sibling to Jason. Not because he didn't like you, but because he did like you. But in a more than family way. So neither of you considered each other as relatives.
You two got close over the years. Flirting during training and sparring, spending quality time together, sharing your interests with each other, cuddling and falling asleep watching stuff together, the list went on. Basically, you couldn't go one minute without giving each other some sort of affection.
That was until everything changed when Jason died. You changed. He came back to find you had gone crazy basically. You were a homicidal maniac. It horrified him, disgusted him even. It hurt him. But he couldn't stand the person you had become.
After all this, a couple more years passed before Tim and Damian came along. He had gotten better, but he still couldn't help the expression he made and the feeling he got when he heard anything about you.
During a calm day, Bruce sent Dick, Jason, Tim, and Damian out on a mission to catch a criminal in an active robbery. A simple mission like any other. They bet on who would catch the villain first as they made their way to the robbery sight.
When they arrived, they didn't see or hear anything that would indicate a robbery. When they tried getting in touch with Bruce over the comms, they realized they were cut off. Then, they heard a laugh from the alleyway. A laugh that froze Jason.
He made them stay back as he went to check out who was in the alley. It couldn't be.. But it had to.. it sounded so much like you.. He just had to make sure. To be safe. To give himself some closure.
"Hello..?" He asked cautiously down the alley.