"AITA for potentially breaking apart my family?"

I'm on a throwaway account. I'm 16 and have one sister who is 19. I'm closer with mom and my sister is closer to my dad. It's just always been like that. She's the perfect daughter in his eyes because she's saving herself for marriage and all that while I'm more "wild" in his eyes.

I'm not saying I'm boy crazy or anything. It's just his definition of wild is me wanting to get a second earring or a splash of color in my hair. I keep a diary. I love writing and it helps me vent. Last week I saw a crumbled piece of oreo in my closet. My sister loves oreos and my dad always makes sure we are stocked with them even though she's the only one who eats them.

I immediately accused her of snooping which she denied and then the dumbass literally outs herself by mentioning my diary in her denial even though I didn't even bring it up. After more denials she finally confesses that my dad put her up to it.

So apparently my dad was worried I was being "influenced" by my friends to become bi-sexual. I'm not making this up. My dad asked my sister to read my diary to see if I was becoming bi-sexual. I'm not going to get into what was in there but I was furious. Well fair's fair and guess who also keeps a diary and guess who knows where she keeps it?

So last Friday I did a bit of reading of my own. This isn't the AITA part. I already know I'm the a$$hole for doing that and I don't care. She doesn't write in it much and it was actually pretty boring. Ironically her last entry was about reading my diary for my father and there's no mention of feeling guilty. But it was the another entry that led to all hell breaking loose in the house.

She just referred to it in an unrelated passage but it turns out that my dear religious father had an affair. My sister referred to it in the past tense so I knew it was over (I found out later that it ended 4 or 5 years ago). I felt like a gigantic grenade had just gotten tossed into my family. Obviously I'll never look at my dad the same way again.

I agonized about it on Saturday. I only confessed to my mother about reading my sister's diary to see if she would give me any indication whether she already knows about the affair. Either she doesn't know, or at least she doesn't know that my sister knows. At that point I decided to let it go.

Here's the AITA part. On Sunday I didn't want to go to Church. Predictably my mother mentioned that my father wouldn't like that and I said "Maybe dad isn't as Christian as you think." That's where I messed up. She knew I read my sister's diary and must have put two and two together.

My sister told me that mom confronted her and insisted on seeing the diary and now my parents have been arguing and being cold to each other for two days straight. My sister says I'm evil for manipulating the situation so my mother would find out. I'm feeling super guilty for not just keeping my mouth shut. AITA?

What do you think? AITA? This is what top commenters had to say:

Sadielady3 said:

NTA- You are an asshole for reading the diary, but you already admitted to that. Your dad had the affair, your dad started the whole diary snooping bullshit, and your dad, for whatever reason, decided to confide in his teen-aged daughter about having an affair instead of his wife, which is all kinds of messed up. Your mother had a right to know, regardless of the other circumstances.

[deleted] said:

NTA. Who had the affair? Your dad. Who covered for him? Your sister. Who either knows and chooses to act like she doesn't or chooses not to see it? Your mom. Who's more worried about you being bi than the vows he took? Your dad.

Who doesn't believe in your privacy? Your dad + your sister. Honestly, what you did was kind of karma in a way. While I don't condone reading others' journals, you're not asking about that bit. So, NTA.

And sdfre2580 said:

NTA. funny how he thinks being bi is so bad but adultery isn’t!!!!! gotta love pick and choose religion. he got what he deserved. and your mom deserves to be free from him.

She later shared this series of dramatic updates:

1.) My mom just came to talk to me. This is worse than I thought. She didn't outright say it but they are talking about a divorce.

2.) It's hard to tell but I think my dad is in the bedroom packing. I know I shouldn't be talking about this online but I'm freaking out.

3.) Sister just confirmed my dad is staying in a hotel tonight. Thank you all for your comments and support. I cried earlier and didn’t want to give an update until I felt calmer. I don’t really have anyone to turn to beyond my sister (too embarrassed to tell any friends) so I really appreciate you guys spending your time writing all of this.

My mom is currently in her room and asked us to give her some space. My sister and I plan on insisting on a family meeting in the morning when everyone has had a chance to sleep on it.

4.) First I need to thank all of you so much for your support. Please believe me when I say IT MATTERED SO MUCH! My sister and I stayed up late reading it and it actually helped us talk out our issues. All good things too. I wish I had better news about my parents but we are hoping that my mother comes around. It's just all so new for her I think.

My mother refused to have my father in the house but she finally agreed to a zoom meeting as long as she didn't have to see his face. She just stood off to the side during the whole call. My father is pretty much begging my mother for another chance. Basically my mother said she hadn't been happy for a long time and has given up past opportunities to keep the sanctity of the marriage.

Now that she knows that my father was playing by a "different rulebook" she wants to pursue some of those opportunities. I know my father is an a$$hole but it was really hard seeing his face.

I know what he looks like when he's holding back tears. I'm hoping my mother is just trying to teach him lesson and will let him come back home. We still have haven't told anyone else. I feel like as soon as we do there will be no going back. This has been really hard for all of us.