AITA for Walking Out of My Sister’s Wedding After Finding Out She Was Marrying My Ex Behind My Back?

I’m 25F, and my younger sister is 23F.

Growing up, we were extremely close. People used to call us “best friends” more than sisters. We shared clothes, secrets, late-night talks — everything. Even when we fought, it never lasted long.

That’s why this hurts so much.

Three years ago, I dated a guy for almost two years. He was my first serious relationship. I genuinely thought I was going to marry him someday. I loved him deeply, even during the hard times.

But near the end of the relationship, he started becoming distant. He’d cancel plans, ignore my texts for hours, and somehow always made me feel like I was asking for too much just for wanting attention.

Then one day, out of nowhere, he broke up with me.

His exact words were:
“I just don’t feel the same anymore.”

That breakup destroyed me.

I cried for months. I stopped eating properly, deleted social media, and honestly became depressed for a while. My sister was the person comforting me through all of it. She’d stay up with me while I cried, tell me I deserved better, and constantly reminded me that one day I’d look back and realize losing him was a blessing.

Again… that’s why this hurts so much.

About eight months after the breakup, my sister suddenly started acting weird around me. She’d hide her phone screen, leave the room during calls, and get defensive over small questions. I noticed it, but I never imagined the truth.

Then one night, I accidentally saw his name pop up on her phone.

At first she claimed they were “just friends.”

I remember feeling uncomfortable, but she promised me nothing was happening and even accused me of being controlling for caring who she talked to.

A few weeks later, she admitted they were dating.

I felt physically sick.

She swore they only started talking AFTER our breakup, but honestly I never fully believed her. The timeline felt too suspicious. Still, she begged me not to ruin our relationship over “something she couldn’t control.”

My parents took her side immediately.

Their argument was basically:
“You can’t control who people fall in love with.”

So I stayed quiet.

I stopped talking to him completely and tried pretending I was okay for the sake of family peace. Inside though, every family dinner felt humiliating. Watching my own sister hold hands with someone who once told ME I was his future felt like torture.

But it got worse.

Last year they got engaged.

And apparently everyone knew before I did.

My parents helped plan the proposal. My cousins celebrated it. Even my aunt admitted later that she thought I “already moved on by now.”

Nobody cared enough to ask if I was actually okay.

I still attended family events because I didn’t want drama, but I kept my distance. I never insulted them, never exposed anything, never caused scenes.

Then came the wedding.

I honestly didn’t even want to go, but my mom begged me. She said if I skipped it, people would gossip and it would “ruin your sister’s big day.”

So I went.

The entire day felt like emotional torture. Everyone kept talking about how “perfect” they were together while I stood there smiling like an idiot pretending my heart wasn’t breaking all over again.

Then during the reception, my sister grabbed the microphone to give a speech.

At first it sounded normal. She thanked everyone for coming, thanked our parents, talked about love…

Then she looked directly at me.

In front of EVERYONE.

And said:
“I know our relationship wasn’t always perfect, but I’m so happy my sister eventually supported our love story.”

People started clapping.

I don’t know what happened to me in that moment, but something snapped.

Because that wasn’t true.

I never supported it.
I just stayed silent because everyone made me feel selfish for being hurt.

So I stood up and said:
“No, actually, I never supported this. I just got tired of being treated like the bad guy for being betrayed.”

The room went completely silent.

I started crying and said it was disgusting that my own sister dated the man who broke my heart while pretending to comfort me through the breakup.

Then I walked out.

After that, chaos exploded in the family.

My parents are furious because they say I humiliated my sister at her wedding. My sister texted me saying I ruined the happiest day of her life out of jealousy and bitterness.

But honestly?
What about the years of humiliation and pain THEY caused me?

Several relatives are saying I should’ve stayed quiet because “the wedding wasn’t the place.” Others secretly told me they understand why I finally broke.

Now half my family isn’t speaking to me.

So… AITA for walking out and exposing the truth during my sister’s wedding speech?