Why would anyone purposely plot against their own brother?

[Anonymous]

I'll refer them as Anna and John. I've been friends with Anna since 7th grade. John was a year older than both of us. I had art classes with John and instantly had a crush on him.

During our freshman year, I confessed to Anna about it but told her to keep it a secret. However, he found out about it 2 months later. Supposedly he had overheard us at the cafeteria during lunch. Sometimes he would briefly stop by to say hi to us and leave. The following month, Anna told me she had bad news to tell me. She said that John told her I was the 2nd ugliest girl at school, that I would shoot myself for him and that he'd rather drown in the pool than kiss me, oh yuck, etc. Obviously I was devastated.

A week later, he stopped by to speak to us and wanted to get to know me more. I was too upset, told him he was garbage and an argument formed. We never dated. Years later in our 20's, he requested me on FB and I added him. He had something to tell me about Anna. He recently found out Anna plotted things against his recent relationship and another one years ago, causing a break-up. It turns out he never told her those horrible things about me at the time. She lied about it all, everything. He said his sister has been plotting against him for years, even during their younger years.

I'm shocked. So what type of friend did I have the whole time? Why? Why would anyone do that to their own brother?

Updates

+1 y

Needless to say, I felt horrible for that misunderstanding back then. She's been responsible for the break-ups and other girls losing interest in him. She savaged it all, purposely making him look bad with other girls, even with me.

[Cutegirl06]

Some people are just horrible towards their siblings. Thing is she probably made stuff about you too. If she'd do that to her own brother.

[Asker]

I agree with you on that. If she was capable of doing that to her own flesh and blood, then with friends like her who needs enemies?
I never really stopped liking him after all these years though but was hurt at the time. I've apologized for that misunderstanding and the fact that he never said those horrible things. Feels so awful. We plan on meeting on Saturday.
He can't understand why her sister would do this to him. He loves her sister but she doesn't reciprocate. She had jealousy towards him for years, hated that he's the oldest child and thinks their parents prefer him over her but it's even. Their parents always loved them equally. The last he told me is their parents are taking her to a psychologist.
Wow... so much drama and no much misunderstanding created. I'm glad I'll finally meet up with him on Saturday though.

[Cutegirl06]

I'm happy that everything turned out good and you'll be meeting him soon. I love happy endings 😌

[Asker]

Thank you. Yeah I look forward to our meeting, finally we'll follow up what we could never do long ago. I just feel terrible for the sister he has. She has always been jealous of him being the older sibling.

[Anonymous]

Someone who is very toxic.

[Asker]

I can't imagine ever doing something like that to my own younger sister. The sad thing is her brother loves her and is sad to find out all that about her.
The update is I'll finally meet up with John this Saturday. I never really stopped liking him. I was just hurt at the time and didn't know my Anna was a liar the whole time.