The first time she sees him, she is crying.
It starts with the sorting. When her name is called, Bellatrix walks confidently, she is sure she is going to be sorted in Slytherin. She is a Black after all, and Black are always Slytherins.
So when the hat cries out "GRYFFINDOR!", she freezes.
And the whole hall freeze with her. Not a single clap or cheer, nothing. While a dying family, Blacks are still known and a Black in Gryffindor is almost unheard of.
The faint tinge of pink in her cheeks is the only sign that she feels something. With her face pure blank, her head held high, Bellatrix walks to the Gryffindor table, she doesn't care no one applauded, she is a Black and she doesn't need anyone's approval.
Expect her mother, that is.
When the next day comes, and with the next day the owl post, the thing that Bellatrix is the most afraid of happens.
An eagle owl drops a Howler right in front of her.
And she wants to scream and cry and vomit and- she knows exactly what this means. With a calm move, she opens the letter, and a second later, the voice of Lucretia Black née Rosier fills the hall.
"BELLATRIX BLACK! YOU ARE A DISGRACE! GRYFFINDOR? I DID NOT RAISE YOU SO YOU COULD GO AND CONFER WITH BLOOD TRAITORS AND MUGGLEBORNS. MUST YOU ALWAYS BE SUCH A DISSAPOINTMENT? WHAT WOULD YOUT FATHER THINK? HE WOULD BE ASHAMED TO CALL YOU HIS DAUGHTER MOST CERTAINLY. A TAINT ON THE NOBLE AND MOST ANCIENT HOUSE OF BLACK! YOU SHOULD BE VERY CAREFUL HOW YOU BEHAVE YOUNG LADY, A TOE OUT OF LINE AND YOU WILL END UP LIKE YOUR UNCLE! DON'T SHAME YOUR FAMILY EVEN MORE THA-"
She doesn't remember when the shouting stops or when she stands up and leaves the hall. She doesn't remember sliding down a wall in a corridor no one has been in a while from the look of it, and she doesn't remember when she starts crying.
That is how he finds her, a small little girl with a wild mane of raven black hair, wrapped in a ball and whimpers coming.
"Hey! Are you okay? What happened?"
Bellatrix tenses, no one should have seen her like this, not even with red eyes and tear stains on her cheeks let alone actually witnessing the crying. Crying is for the weaks and Blacks are not weak.
She raises her head and looks at him, and mutter with a snappish tone.
"Don't you know what happened? I'm sure everyone in the Great Hall heard it."
He sits next to her.
"Ah, well you see I hadn't been in the Great Hall yet. I slept a bit late and no one really bothered to wake me up so I could eat before class it seems. So what happened so bad on the first day of school that it made a firstie cry?"
"I got a Howler."
"What?! On the first day of school? How did you manage that?"
"I. . got sorted in Gryffindor."
"Wh. . . Oh! You're the Black girl. Bellatrix, was it? Yes I reckon that would be bad."
"Yes it is."
"I'm not sure if it would make you feel okay, but dad wante me to get sorted in Gryffindor and I got in Hufflepuff. You're not the first one to shame their parents with their house." There is a slight bitter tone in his voice, Bellatrix realizes.
"I'm sure your parents would not disown you for getting sorted in Hufflepuff though."
"Wait what? They would do that to you?"
"Contrary to the belief of many people, I am not the first one in my family to get sorted in Gryffindor. My uncle was too."
"What happened to him?"
"He got disowned when he was sixteen. He is in Azkaban now."
"Wow, that seems a bit harsh."
"Hmm-mmh."
". . ."
"What is your name anyway?"
"Cedric. Cedric Diggory. Nice to meet you little Black."