"AITA for going home with my brother-in-law?"

To make this long story short my fiance 29M, his brother 24M and me 25F were on a party with my fiance Side of the family and they can get pretty wild partying until literally the next day.

I'm not used to this kind of events nor do I drink much but I had a couple drinks at the party around midnight my head hurt, I was tired and I felt dizzy so I asked my fiance to take me home and he said soon but 1 am came and he was still dancing around with his cousins my bil sat next to me and said I'm heading home would you like me to take you too? I said yes and I texted my fiance telling him I left already.

When I came home I realized I didn't have the key because it was in the same keychain as the car keys so I was unable to enter home I was frustrated I was almost I tears because my head was hurting so bad, he then asked me if I wanted to crash at his place and I thought about it but I didn't want to wait for my fiance to get home at probably 7/8 am so I agreed and we went to his place (he lives about 20min from us).

He offered me his bed and he went to sleep on the sofa, I fell asleep instantly and woke up around 11 am I grab my phone and found 30+ missed calls and like 100 message from my fiance I called him and he starting asking me were was I and why I wasn't answering. he was yelling and panicking and I told him I was at my bil's house and he hung up without answering.

I went to wake up my bil and not even 15min later my fiance was already there yelling and accusing us of cheating he realized I was wearing my bil's clothes and freak out even more, I tried to explain that nothing happened because we don't have that kind of relationship but he didn't believed us, then he stormed off but 5 minutes after came back and grab me and take me home with him.

He asked for my phone and I gave it to him and after not finding anything he still thinks I have something with his brother he told his entire family he was cutting bil off and won't talk to him ever again but didn't tell anyone why, he then said I need to work extra hard for him to forgive me and we need couple's counseling but only after I confess what we did.

But literally nothing happened I was just extremely tired and I know him for 6 years so I decided to go with him, I talk to my mom and she said I disrespect my relationship by going home with another man and I shouldn't be surprise if my fiance call our engagement off.

I love my fiance very much but I never saw him like this and I don't know what to do. My mil calls me constantly asking me if I know what happened and why would my fiance treat his brother like this and I don't know what to tell her.

I was just too tired and my head was killing me so I went home and now I don't even know if my relationship is salvageable.

Edit to clarify something: A lot of y'all are asking why I didn't tell my fiance face to face that I was leaving with bil and that's because I knew he would have stopped me and told me he would take me home and then keep me waiting for him. I know I didn't do everything the right way but my head was killing me and I was tipsy.

As for the t-shirt I thought sleeping in a crop top with no bra was worse than asking for a t-shirt to cover myself. And why didn't I ask bil to text his brother? It didn't even cross my mind at the time. Plus my fiance and I have that thingy where you can check where the other one is ( I don't know what name it has on Android)

This is what people had to say to OP:

Next-Firefighter4667 said:

God. Tbh, I couldn't deal with any of this from either side. I'm glad I married a man who would prioritize me over partying and let me know where he's going because I leave enough space for him to actually do so. All of this is exhausting.

He thinks you cheated (why on earth he thinks this is how you'd cheat, in the stupidest manner ever, who knows). Even if you didn't, it's over. You can't have a relationship without trust, trying to make it work will be torture for the both of you.

Even_Memory3298 said:

If I was the BIL I would have texted my brother and told him what was going on. Also would’ve called him out on being a POS. That’s just me though.

witchbrew7 said:

He refused to take you home. You left. He had the key. Your BIL offered an alternative. Your guy is not a good partner and he behaved very badly.

NTA but this sort of thing would make me reevaluate the entire relationship. He screwed up and is punishing you for trying to advocate for yourself.

Two days later, OP shared this update:

Hey it's me again this time I'll put a TL;DR at the end because sh!t got complicated and I don't know how exactly to explain it all.

So first of all I checked my ex's phone I know you're not supposed to do that and people's deserve privacy and what not but quite a lot of people said he was probably projecting so I wait until he fell asleep and I checked it well long story short he is cheating and for about a months now I don't know the girl but for what I saw in the conversations it seems like she is a coworker?

Idk I was shock and a little sad but somehow relieved? Because at the end of the day it seems like he was just trying to make me feel bad because he was the one doing something wrong behind my back.

So, the next morning around 5 am he went to work and I packed my essentials and went to my sister's house, I explain the situation and her and her husband were more than happy to let me stay my bil ( my sister's husband let's call him Lucas) told me he could go with me later if I wanted to retreat more of my things and I said maybe.

I also went to my ex mil's house just to talk more than anything, my bil (ex's brother let's call him Frank) was also there I don't know if mil called him or if it was just a coincidence but I told my mil everything that happened including the cheating which I had proof because I took pictures of his phone with mine, she was horrified and started crying but the thing is Frank said he did text my ex.

He show us the texts and there were like 10 from hey I'll take her home because you're an alcoholic", "She didn't have a key I'll take her to my place and even a selfie where I was passed out on the bed in the back "she is safe come take her tomorrow."

So that was weird because when I checked my ex's phone I didn't see any texts from Frank so he either deleted them or he blocked his brother, and also mil said she woke up around 6:30/7:00 am and nobody was in her house anymore so ex wasn't there partying till almost 9am when he started to called me.

I had some mix feeling and I cried a lot but I didn't have any energy left to ask my ex for answers. I just sent him a text telling him it was over and I moved out and blocked him but my dumbass forgot to turned off the share location so he showed up to my sister's house, and staring crying and asking me if I don't love him anymore and whatever.

I didn't want to disturb anyone else so I invited him in just because Lucas was home and felt save enough, he started babbling again about love and stuff and I just told him I knew about his affair, his face instantly change and he stopped crying it was a scary tbh I never saw him like that he just said that didn't mean anything and I was the only one who can be his wife.

I was like mmm not thank you, he got very agitated and tried to grab me, I scream and Lucas came thankfully very quickly and kicked my ex out and told him he wouldn't let him go very easily next time if he try something like that again.

I just cried a lot and started to have probably a panic or anxiety attack because I felt like I couldn't breath I don't remember much really after that other than waking up in the middle of the night with my sister next to me, it felt safe to be with her I just fell asleep again closer to her.

her and Lucas want me to make a police report because he got aggressive, I don't know if they'd do anything because he didn't hurt me but Lucas said he would be my witness if I need it and he would go with me to make the report as well.

I called my ex mil today again to tell her what her son did, I think she needs to know I told her I really love her but I don't think I can keep contact with her after what happened, Frank tried to called me a couple times too but I don't really have the energy to do so.

My sister's said her and Lucas are moving next year for work and I should come with them to the new city and I think I'll do it because I don't think there is anything else for me to do here. She is the only family I have left so why would I stay far away from her?.

I think that's all if y'all need more context or something just tell me I'll clarify if I can and Merry Christmas?

TL;DR: Ex accused me of sleeping with his brother, he was the one cheating and when I broke up with him he got aggressive