In the story, posted to Reddit's anonymous "Am I the A--hole" forum, the woman breaks down this issue that's been going on for years and the decision she made about it in a moment of frustration.

While she started to wonder if she'd gone too far with her demand, Redditors almost completely ignored her specific AITA query to dig far deeper into the overall situation -- leading to an unexpected update from the OP (a.k.a. the "original poster").

Read on to see the full story and how Redditors reacted.

This one has a little more history to it, but that's only because OP jumped back on to Reddit with a major update based on reactions to her initial story, which now follows.

"My Fiancé and I have been together just under 6 years (dated 3, engaged 2.5) . Great relationship relatively, our friends & family all get along well with the other person, no issues at all…" writes OP, "EXCEPT for one of my partners best friends."

She goes on to claim that she believes this BF "has never liked me and seemingly had it out for me the entire time." OP says that her fiancé's BF ignores her, even refusing to speak to while interacting with her fiancé and even in group settings.

"I told him about it & how it made me feel & at first it went unaddressed 2-3 more times because he 'needed proof' to make sure there was an issue," OP explained. "After said 'proof' was present he spoke to her about it & she got a little better, but only around groups of people and like twice."

"She indicated she doesn’t have a problem with me, so he felt I am the only one having an issue and I need to just approach her and talk it out," the post continued. "I told him I’m not doing that cause she isn’t my friend and HE needs to do so."

That was how things were, but the actual incident that drew OP to seek advice from Redditors came "a couple weeks ago" at a party. The couple and the BF were both there, with OP saying she tried to say hello and make eye contact, but BF "avoided me and refused to look at me the whole time." She said it was so "blatant" her fiancé even noticed.

"I don’t want her respect, don’t need her to like me, don’t honestly want her around at all, I just want her to have basic human decency," OP said.

But the incident also left her rethinking her relationship -- and even considering ending it -- because, "I feel my fiancé is in the wrong for engaging with her after seeing how she completely disregards me. I think now but mostly after marriage we’re supposed to be a unit and I wouldn’t allow this behavior from a friend."

She said she now feels "like an a--hole" because they spent the night arguing and she laid down the ultimatum that his best friend could not come to their wedding.

Redditors almost immediately ignored the "AITA for telling my fiancé she can't come to our wedding" as the least of OP's problems, though one did reply blunt, "You should have told him that he can’t come to your wedding."

One comment, with more than 2,000 upvotes, summed it up concisely: "NTA but I am surprised that you decided to marry someone who allows such behaviour toward you."

OP replied to that one, arguing, "I don’t want to ruin what has otherwise been the healthiest and best relationship in my life but I’ve been thinking on it hard.. because where are the boundaries?"

The commenter went on to tell OP that what's happening with the BF isn't just being distant, "she pretends that you don't exist." They argued, "A good partner wouldn't keep her as a friend." OP said that the BF "acts very much like a high schooler" and believes "she thinks she is his number one and he'll choose her if it came to the wire."

"Here's the thing OP, he HAS basically chosen her over you almost every time," the Redditor returned, asking OP, "Why is he okay with hurting you, the person he is in a relationship with, to avoid conflict with his friend?"

Some called out OP calling this the "healthiest relationship" in her life, suggesting she "might want to take a break from dating and focus on therapy," calling her fiancé "the very low end of the dating pool."

OP defended her fiancé, though, replying, "He definitely isn’t the low end of the dating pool, he’s the upper end which is part of the problem. You brought up valid points, which I appreciated. There can’t be a compromise with this at all." She also told another commenter that after this final blowup, her fiancé told her "he won’t acknowledge her if she doesn’t acknowledge me, but I feel like it shouldn’t have taken years to get here."

To this another Redditor shot back, "Girl. A man who doesn't put you first is the low-end of the dating pool."

"NTA -- but your fiancé is," wrote another Redditor. "Had he ever asked what her f--king problem is? Take a hard stance on no invite." While OP she and her fiancé have gone back and forth on this for years, with fiancé telling her BF keeps insisting she has no problem with her, one commenter decided to be blunt with her.

"This will be hard to read, stop bringing it up. He’s made his choice very clear and he’s not going to change," they wrote. "YOU have to decide if you are willing to accept that behavior in your partner and if the answer is no, leave. He’s had plenty of time to fix this, he hasn’t. Stop asking him to choose you and choose yourself instead."

More details brought up even more red flags, as one commenter bluntly wrote, "She's in love with your man." This led to a huge revelation from OP, who commented that she's heard this from others, and shared, "There were times on social media where she indicated she was the ideal woman for him / that he needs someone like her."

Other Redditors picked up this thread and took it to a fairly logical conclusion, with one writing, "If they're not already f--king, at least one of them is actively plotting to do so."

In one moment, OP conceded, "I’m thinking (and these comments made me realize) I don’t want to marry someone that is okay with someone, esp a close friend, disrespecting me his future wife."

"I am so sorry that you have had to come to this realization, but so damn proud of you for getting there 👏👏" replied a Redditor.

All of the above was just under a month ago. Now, in a fresh update, OP shared just how much all the advice from Reddit impacted her and how she moved forward after giving her fiancé that ultimatum about his BF.

"The comments on my original post opened my eyes and made me realize that despite this being the healthiest relationship I’ve been in, it doesn’t mean it’s actually healthy," OP started, sharing that subsequent conversations about the issue with her fiance circled the same points: she said it bothered her, he said she was the only one who cared.

She continued: "A couple things helped me realize my breaking point-

1. I asked him if he would be okay with our daughters future partner treating them like this, to which he got flustered, shut down, and said he didn’t want to talk about it. (I left it alone)
2. He said he didn’t want to end his friendship or do anything to jeopardize it because “what if we break up.” This made me realize he would not protect me as his wife, since he didn’t as his girlfriend."

Then, OP shared her "final straw" came when her fiancé told her she should just "blow this off" since she and his BF only see each other four to six times a year.

"He said (directly quoted because this is burned into my brain) : 'I know the way she treats you is garbage, but you’re allowing one person to dictate our relationship. It could be worse. She could be more active. There are worse ways to meddle, people text and lie, and all that to break relationships up.'

She said that first line "broke my heart and told me all I needed to know," and she "closed the curtain on any chance of healing this relationship the moment those words left his mouth."

She thanked Reddit for coming through with "the advice, common sense, knocking me upside my head," and said she would be seeking therapy to "redefine what a healthy, balanced, and communicative relationship." She also said, "There will be no second chance."

This is a pretty major decision, too, as an edit to the post revealed that they currently "share a home, need to divide assets, pets, a custody schedule."

She also addressed those people theorizing her ex-fiancé and his BF were sleeping together, by admitting, "probably." She added, "When I first brought this up, he became stressed & kept emphasizing how I thought he was f--kin his best friend, and didn’t address the issue that was brought up," she explained. "I don’t care to know or confirm."

OP summed up her own journey, writing, "I NEVER asked him to cut anyone off, out of his life. I simply asked for basic greetings & acknowledgment during the rare encounters with his BFF. This hasn’t happened, aside from a couple of begrudging times."