OP (a.k.a "original poster") shared her story on Reddit's infamous AITA ("Am I the A--hole") forum, revealing that she may have let something slip about her sister prior to the wedding which caused her brother-in-law to feel uncomfortable. She has now been blamed for "ruining" the wedding and subsequent honeymoon, causing her parents and brother to get involved.

Read on to see what went down, and how Redditors reacted.

"So I (20F) have an older sister (30F), who I'll call Emily. Emily got married 2 months ago to her partner Danny (34M). My siblings and I grew up together and Emily was a huge influence, along with my other older sister Mary (27F). They were both wild and so, from a young age, I knew a lot more than I was supposed to (about partying, dating etc. nothing weird or scandalous really). Mary got married 4 years ago and I'm really close to my brother in law. He knows about her partying, drinking and pretty much everything else she did and he never had a problem with any of it," OP began, explaining the scenario.

"Well, I've met Danny only a handful of times since they live far away and so I assumed they talked about it all. Come wedding rehearsal (the day before), we started sharing interesting stories from our childhood. Danny asked me how come I've never dated, drank or partied. I, not even thinking it might be a big deal, said that after hearing all the stories from my older sisters, never really wanted to or felt the need to. Danny looked a bit confused but said nothing. Mary just glared at me. Later, Mary told me Danny knew nothing of Emily's 'wild days,'" she continued, before adding that she apologized to Emily, who said it "wasn't a big deal".

Time passed and OP presumed all was forgotten. In fact, she hadn't even thought about it for "two months," that is until ...

"Emily and Danny visited us yesterday. Danny was as nice as ever, while Emily was a bit standoffish. While Danny was out with our dad, Mary and Emily ganged up on me and told me Danny was mad at Emily for lying and that I ruined their wedding and honeymoon," OP said before adding that their mother came in to defend OP.

"My mom heard us talking, came into the room and chewed out my sisters for blaming me for Emily's lies. After they went to my sister's place (they were gonna stay with her for a couple of days prior to this incident), I started feeling anxious and bad about what happened and the part I played in it. My mom told my dad and brother what happened and they both said I did nothing wrong and my dad said he would make my sisters apologize, but I don't want them to get involved," before she asked Redditors if she was an a-hole "for ruining my sister's wedding and honeymoon?"

Along with OP's mother, Redditors also come to her defense -- with the majority telling her she wasn't in the wrong, before the post received an official "Not the A-hole" badge.

"How are you supposed to keep with the lies if you don't know there are lies to keep up with?!?!," one social media user said. "It's pretty much common knowledge that wedding rehearsals are time for good natured teasing of the bride and groom. Emily and Mary should have seen this coming and warned you. (And it's not even like you gave sordid details!) NTA," they continued.

While another said OP's sister was "trying to shift the anger."

"Of course you are NTA. Trying to shift the anger onto you is what makes your bride sister one and the other one assisting her especially. She should have owned up to her lies as it would most likely have come out in the future anyway (or were they planning to go NC with everyone who knew your sister in her 'wild phase'?)," they said. "Her poor husband, learning about your bride-to-be's probably promiscuous past and being lied to definitely puts a damper on ones wedding celebration and honeymoon. The timing was unfortunate but better before than after the wedding."

Another wondered how OP was even meant to know what her sister has or hasn't told her husband.

"NTA - you're definitely not the a-hole in this situation, how would you have known that Emily did not tell your BIL about her past? Additionally, if Emily did not want Danny to find out, she should have warned everyone to keep quiet about it," the Redditor said. "Your sister should just own up to the consequences of lying to BIL instead of playing the victim and blaming you."

After receiving hundreds of comments, OP revealed an update after having "the talk" with her sister, shocking her fellow Redditors in the process.

"Basically, my sister and BIL are both idiots (with much love). Turns out my BIL was upset she didn't tell him everything, but he got over it quickly. He didn't mention anything for almost 2 months because he thought Emily was upset with herself and the situation, so he didn't want to make it worse," OP said in the update, before revealing that the couple actually ruined their own wedding and honeymoon.

"Now, my sweet idiot sister though something similar, that he was upset with her, so she didn't want to make the situation worse than it already was. So, basically, the wedding and honeymoon were 'ruined' because they had an awful case of worrying about the other one and walking on eggshells around one another. My BIL was never upset with me and my sister wasn't really upset with me either," OP insisted.

"Before visiting us yesterday, Emily went out for a coffee with her friend Lexi (~30F). Lexi had always been ... Interesting ... She's one of those people who only care about themselves and are never happy for their friends. Don't ask me how Emily hadn't noticed. As friends do, Emily confided in Lexi and she told her Danny is probably preparing to leave her and that's why he's distant (plus that she deserved it). So Emily went to my sister's upset and later we had the disagreement," OP continued before adding that both of her sisters "apologized for attacking me and to the rest of the fam for the stress."

"Later yesterday, they went to my sister's and Emily started crying while she thought Danny was out. Danny heard her and they finally talked it through. Their conclusion was that they were both idiots 😂 The cherry on top was the fact that, about a week before visiting us, Emily found out she was pregnant (pre wedding baby, I was told). So, when she went to my sister crying about a possible divorce, she told her she was pregnant," OP said.

"I guess that's why Mary took her side. I apologized to both Emily and Danny for the part I played in this mess and they said what y'all said too, that I can't lie about something if I don't know I'm supposed to and that I shouldn't have been put in that position in the first place. So, as of now, Lexi is out, we're all fine and I'm getting a nibling next year. And Danny and Emily decided to have a do over honeymoon on their anniversary next year with the BeBe (Moira Rose anyone?)," OP concluded.

What do you think?