I was closest to my sister growing up. She was the youngest of my siblings but still a decade and half older than me.
She doted on me constantly. It was sweet. I was very close to her as a kid.
Then I came out and transitioned.
She couldn't bother to gender me consistently. I know, from the regular "he/him" slip ups, that she didn't actually think of me as her sister.
Our relationship died by degrees over the years. Her being an inveterate right wing racist asshole accelerated the process...