He is disgusted by you. He sees Bellatrix in you. He can't even face you straight. He doesn't wanna look at you. You look exactly like Bella, (before she went to Azkaban), speak like her, act like her, hell he even suspected that you shared the same views as Bella. He didn't want this for his child.

He preferred Harry over you because of this reason. And because of this reason you despise Harry. He knew it probably wasn't a good idea for you to come to Grimmauld Place 12. Although it was now the HQ of the Phoenix of the Order it was formerly the house of Black. But still, you were potentially in danger and he wanted you safe no matter how disgusted or frightened he was by you.

When news of Harry coming to Grimmauld 12 Place, you felt pissed cause you knew Harry would take away all the attention of your dad away from you. You went over to your dad who was in the kitchen.

"Is it true Potter is coming?"

"Yes. Harry is coming and- Please...be friendly, or atleast neutral to him."

Sirius says in a slightly soft and his voice sounds like he was almost begging.