Hey guys, I really need some advice because I’m feeling so torn. My childhood best friend—someone I’ve been close with literally since we were babies—ended up dating my older brother. She always had a crush on him, and they’ve been together since 2021. Ever since they got together, our friendship slowly faded, and now we’re pretty much not close at all.

But recently, I found out something that’s been weighing on me heavy. In 2022, and ever since my brother started talking to our sister-in-law’s niece—and not in a friendly way. He asked to kiss her (it didn’t happen though) and has been sending her freaky texts, and showing interest in her ever since. She also has a boyfriend currently and has made this clear to him. And the worst part? He’s still with my ex-bestie.

What makes this even more heartbreaking is that she’s been going through so much. Her dad recently passed away from cancer, and it was bad. He was a father figure to me too, so I’ve felt that loss deeply. On top of that, she’s in her final year of university, struggling with depression, she’s gained weight, and it’s clear she’s hurting. She’s not the same person right now—she’s broken, and it’s hard to watch, knowing that my brother is deceiving her.

It’s also always felt uncomfortable that she got with my brother—she knows that. So if I tell her what he’s been doing behind her back, I’m scared she’ll think I’m just trying to sabotage their relationship or get back. Like I’m trying to win her back as a friend by ruining what she has now. As it’s coincidental but I am also going through a breakup, in which that relationship started around the same time as hers. These are both our first relationships. But the truth is, I don’t want to see her being lied to or hurt even more than she already is.

I genuinely don’t know what to do. Would you tell her? And if you did, how would you?