AITAH for Telling My Sister I Hooked Up with Her Fiancé and Ruining Her Engagement, Even Though She Took Him Back?

A woman revealed to her sister that she had previously hooked up with her fiancé, Christopher, before their engagement. Despite initially breaking off the engagement, the sister reconciled with Christopher, believing his claims that the affair was a mistake.

Now, the woman is being ostracized by her family, accused of sabotaging the relationship out of jealousy. She questions whether she did the right thing by telling the truth or if it only caused unnecessary fallout. Read the original story below…

‘ AITAH for Telling My Sister I Hooked Up with Her Fiancé and Ruining Her Engagement, Even Though She Took Him Back?’

I (19F) come from a super religious family where everyone marries fast through matchmakers. I’m the black sheep because I left religion and started dating casually. My sister Marie (25F) is the family favorite—beautiful, smart, outgoing—but she’s struggled to find a husband.

After a string of failed matches, she finally got engaged last month to Christopher (30M). Everyone was relieved because she’d been trying for so long.
I was happy for her—until I met the fiancé.Christopher and I hooked up last year. For context, the age gap between us isn’t the issue, so please don’t bring it up.

We met at a party, and despite being religious, he’s divorced and didn’t seem concerned about “staying pure.” We hooked up five times. He was my first *everything*—kiss, hookup, all of it. After the fifth time, he said he was falling for me, but I wasn’t looking for anything serious, so I ended things before it got too complicated.

Especially because I knew he wanted to eventually get remarried, and I was *not* the girl for that. We hadn’t seen each other since—until Marie brought him home as her fiancé. The second we locked eyes, I knew we were both thinking: *Oh, s**t*. Later that night, Christopher pulled me aside, *begging* me not to tell Marie.

He said it meant nothing, it was in the past, and telling her would only ruin her happiness. He texted and called me for a week, saying how much Marie had been through and how I’d destroy her life if I told her.

I kept my mouth shut at first. I didn’t want to hurt her. But the guilt was eating me alive—like I was watching her walk into a disaster. I felt like she deserved to know. So, I told her. At first, Marie didn’t believe me. She said I was trying to sabotage her happiness because I couldn’t stand being single.

I had to show her the texts and photos to prove it. When she finally accepted the truth, she *lost it*. She confronted Christopher, and he denied everything—until she shoved the evidence in his face. Marie called off the engagement. That’s when things *really* hit the fan.

My parents and some relatives told me I should’ve kept quiet. They said I’d ruined Marie’s one shot at happiness and called me s**fish for interfering. Now, I’m not even invited to the wedding. (Yep—they got back together, but I’ll get to that.)

It gets worse: While Marie and Christopher were dating, he randomly called me, saying he wanted to “reconnect.” He was rather vague, but it was obviously a booty call. I didn’t know he was dating at the time, and definitely didn’t know he was dating my sister.

I let him down firmly and didn’t engage because I had no interest. After telling Marie about our hookup, I mentioned this call because I thought she should know he wasn’t as faithful while they were dating as she thought he was—but that backfired *spectacularly*.

Marie accused me of making up lies to tear them apart. Christopher denied everything and said I was obsessed with him. Marie sided with him and called me, quote, a “desperate home wrecking whore.” Since I deleted my call history, I had no proof. It became a “he said, she said” situation, and Marie believed him.

Now, Marie and Christopher are back together, and they’re getting married. She showed up at my apartment a few weeks after the fight, crying. Apparently, Christopher convinced her that what happened between us was just a “meaningless mistake” and that it made him realize how much he wanted to be with her.

I tried to explain that he had told me he was falling for me—not to make it seem like he still liked me, just to show her he’s lying to her about what he felt for me—but she just got angrier and called me a jealous l**r and some other pretty names I won’t repeat before storming out.

Now I’m completely cut off from family events. My parents say I’ve caused enough damage, and extended family members are calling me a s**t both behind my back and to my face. Every attempt I’ve made to explain myself has been shut down.

So yeah, they’re getting married anyway. And here I am, wondering if I just blew up her engagement for nothing. Should I have just stayed quiet? Did I do the right thing, or did I just ruin my relationship with my family for no reason?

Check out how the community responded:

MrsHappyEverAfter −  Christopher is a walking red flag.  Marie is in for a lifetime of unhappiness, for duration of marriage.  Marie will be wondering if he is really going where he says he is, is he cheating. Their marriage is doomed before vows are exchanged.  OP, you are NTA.

altarwisebyowllight −  So, the age gap absolutely is an issue. A 29 year old already divorced man going after an 18 year old virgin like that suggests he potentially has maturity issues, and maybe isn’t going to be great husband material.

The fact he spouted some “she was just a mistake” b**lshit doesn’t exactly do him any favors, either. You absolutely did the right thing bringing it up, because your sister needs to think really hard about what kind of person he is.

Laila_Serenade −  NTA. She should thank her sister for the heads-up. Better to know now than when they’re married with kids. Some people just love ignoring red flags!

13surgeries −  NTA You tried to warn your sister. Frankly, though, your attempt was doomed to fail. The black sheep of the family ruins her sister’s engagement? (Christopher ruined it, but you’re a convenient s**pegoat.) The very religious family who saw how Marie struggled to find a husband?

You were never going to be appreciated for doing the right thing. Sadly, she’ll realize you’re right about Christopher the second or third time she catches him cheating.

Kurovi_dev −  It would’ve been very wrong to not tell your sister that you and her would-be husband fucked several times. Full stop. End of the story and the sequels. Imagine if they got married and had kids and then this came out after that. Their family could have been ruined, their kids lives impacted

At least now everything is known. She should be thanking you for telling her now instead of after the damn wedding day. He should’ve told her, and that he didn’t is proof that he is very willing and able to keep secrets from her, including ones where he fornicated with her own sister, like wtf. These people are super religious but are apparently very happy to lie.. NTA.

OccasionMundane3151 −  Since I deleted my call history, I had no proof. It became a “he said, she said” situation, and Marie believed him. You can get your call logs from your network provider. Make it a wedding gift, highlight his calls to you, put it in a nice frame, maybe a little bow.

guineababyyy −  NTAH. You did the right thing by telling your sister the truth, and it’s not your fault that she chose to believe her lying fiancé. He was clearly trying to manipulate and cheat on both of you.

Your family may not understand or support you now, but in the long run, you saved your sister from making a huge mistake. Don’t let their words bring you down, you did the right thing and you deserve to be respected for it.

Lambsenglish −  NTA, sister. This will come back and bite her. You did everything you could and can hold your head up high.

Fast_Ad7203 −  Just cut them off back, tell her to not come crying later when he cheats with a newly 18 year old
Do yo you know why some pedos date 18 yos? Because they are the closest to what they fetish on without getting into legal trouble. This dude is a c**ep

terrificblythe −  NTA. You did the right thing by telling your sister the truth. Christopher and your sister’s relationship is built on lies and deceit, and it’s better for her to find out now rather than later. It’s not your fault that Christopher is a c**ater and a l**r, and your family’s reaction is unfair and unacceptable.

You deserve better treatment and support from your family, and hopefully, they will come to realize that in time. Stay strong and don’t let their hurtful words bring you down.

Did she act out of honesty or overstep by revealing the past? Share your thoughts below!