My childhood best friend of 11 years is ending our friendship and I just am at a loss of what to do.

I have a male best friend of essentially 3 years now. We’ll call him Jack. I introduced Jack and my friend, Emma, earlier this year and we became a little trio where we hang out, talk, do things together, etc.

To establish the dynamics: Jack considers me his best friend and vice versa. Emma and I are best friends. SIDE NOTE: I have no romantic feelings for Jack and vice versa.

Recently Emma began catching feelings for Jack and expressed discomfort over me and Jack hanging out by ourselves. Her and Jack start flirting over text heavily and end up hooking up and things kinda take a turn for the worse. Jack feels that them having sex can potentially ruin things a lot between all three of us and decides not to take the relationship further.

He tells her he doesn’t want to change the friendship, she expresses understanding, but she feels really hurt and rejected about it later on. She vents to me, I try to support her as best as I can by giving her advice, etc. He’s also casually dating a girl at this time — she was aware of this prior to the hook up — and she feels really hurt about it as well.

She starts to feel isolated from me — she feels upset that me and Jack are still hanging out alone and she thinks I should be telling her when we do, she tells me she’s going to distance herself from me because I don’t tell her what Jack got her for Christmas, etc.

It eventually blows over to where she’s feeling extremely hurt, I advise her to stop talking to Jack since it’s making her feel worse, and she tells Jack I told her that. Jack ends up distancing himself from her, she feels worse, I try my best to support her and give her advice, but she finally said that she feels betrayed and hurt that I’m still friends/laughing with the guy that hurt her. She feels disposable and that he discarded her after hooking up.

I feel like — is there anything I could’ve done more to prevent this from happening? Was this bound to happen — was it impossible for me to salvage my friendships with both of them? Am I a terrible friend?