Context: https://www.reddit.com/r/AITAH/comments/1k26nyw/aita_for_standing_my_ground_after_i_was/

TLDR: My gf's best friend has been disrespecting me and when i stood up for myself she lost it, and my gf apologized and promised to make changes.

Well guys, fuck me it's been a wild ride. Here's the update I promised. I feel like i've been hit by a semi truck.

I cut off the few friends in the friendgroup that supported my gf's bestfriend (Blake). My gf apologized to me and told me she would talk to blake and set boundaries. I knew when the conversation had just wrapped up because I got a wall of text, initially sounding apologetic until it turned into a "i'm sorry you're so insecure you had to ruin our friendship".

But, what caught my eye was the bottom. Blake fully admitted she thought she was better for my gf then me, and had included a video i'd never seen before. My heart is torn just writing this. She attached a video of her going down on my gf from a year ago according to the timestamps. Upon receiving this, I went to my bathroom and started puking. As soon as I could stand, I forced myself to rewatch what I had just seen. I don't know if this was the first time they hooked up, the only, but at that point i didn't care.

I called my girlfriend and confronted her immediately, she went into hysterics saying that that was before me, that she doesn't have any romantic feelings for blake and wants to cut her off to be with me, and that we could make it work. I'm ashamed but i just hung up on her and sobbed.

I broke up with her. I'm getting bombarded with texts and calls from concerned friends and family wondering why "the perfect couple" broke up. Worst of all, her parents have reached out to me to ask what has happened and if there's any chance we can fix things. They don't know what has happened. Would i be the asshole if I told them their daughter fucked her bestfriend? Ordinarily i absolutely would, but given that her parents are super religious I worry they'll stop funding her college. I'm a wreck and really need any advice you guys have.

I'm not sure how I'll deal with this.