u/BunnyBabeex

I (20F) was with my boyfriend (21M) for about a year when I found out he had been secretly involved with my 18 year old sister. I didn’t hear it directly from them, I actually overheard them talking on the phone and she was panicking while he was basically telling her not to worry about me finding out. I didn’t confront them right away because I was honestly in shock, but a few days later we were all at a family dinner and I ended up bringing it up in front of everyone because I couldn’t hold it in anymore. My boyfriend left immediately and my sister broke down crying and kept begging me not to cut her off, saying she made a mistake and that she wanted things to go back to normal. The problem is she had been staying with me and we were supposed to move into a new place together soon, but after this I told her that wasn’t happening and I’ve been staying at a friend’s since. Now she can’t afford to live there on her own and I’ve made it clear I won’t be living with her again or continuing a relationship with either of them. My family is split, with some saying I embarrassed her and made things worse, and others saying I was blindsided and reacted out of shock. One of my aunts even said I ruined her life, but I told her I’m not responsible for the fallout of what they did. Now I’m being called dramatic and heartless, but I genuinely don’t know if I went too far. AITAH?