“AITA For Telling My BIL That Someone Is Going To Punch His Girlfriend One Day?”

When you look at messy interpersonal conflicts like this, especially around weddings, it’s almost textbook social‑psychology territory. Alcohol, emotions running high, mixed relationship structures, different boundaries, plus a loud personality like Sally — that’s exactly how drama brews. But let’s break this down deeper, because there are layers here involving consent, harassment, gaslighting, boundary violations, polyamory misconceptions, and even some light defamation‑adjacent behavior with her lying about what OP supposedly said.

First off, let’s talk physical boundaries and consent, because this is where the whole conflict really started. A lot of people misunderstand flirting. Flirting is only okay when both parties are into it. The second one person clearly tries to step away, it becomes unwanted physical contact — and that is generally recognized in psychology and even in law as a boundary violation, sometimes categorized as mild harassment depending on intent and persistence. For example, U.S. Equal Employment Opportunity Commission (EEOC) guidelines define harassment as unwelcome conduct that becomes a condition of environment or participation. Sure, this wasn’t a workplace, but the principle is the same: when the other person tries to leave or signals discomfort, it should stop. A wedding isn’t a “free flirting zone.”

What Sally did — cornering someone physically, stepping forward every time he stepped back, touching his arm — is behavior commonly associated with coercive flirting. Studies in social behavior research (for example, the works of Dr. Tara Collins and Dr. Deborah Tannen) show that escalating physical proximity after someone withdraws is a form of pressure, not flirtation. Even if she meant it innocently (she probably didn’t), the effect matters more than her intention. And OP’s boyfriend’s face showed relief when he saw OP approaching — that’s a pretty clear indicator this wasn’t mutual.

Another big issue here is that Sally has a pattern of making her personal preferences into universal truths. Her drunken rant about monogamy being “disgusting” and people being insecure or controlling if they don’t choose polyamory is actually a known behavior in certain personality profiles. It’s related to identity over‑identification, where someone builds their entire personality around one lifestyle choice — and then defends that choice aggressively because they feel personally threatened when others don’t validate it. This happens with diets, political ideologies, parenting styles, and yep, relationship structures too.

It’s also worth noting that in ethical polyamory communities, her behavior is not considered normal or acceptable. Anyone familiar with polyamory best‑practices (Dan Savage talks about this a lot, and books like More Than Two emphasize it too) knows that respect, consent, communication, and non‑coercive behavior are core principles. Sally violating boundaries and then playing victim actually contradicts poly values. So the “polyphobic” accusation she threw out? That was basically a smokescreen. And honestly, very harmful, because using social‑justice or identity‑based language to deflect accountability is manipulative.

Now let’s touch on the psychological side: lying, changing stories, and exaggerating claims. When Sally lied to BIL — claiming OP said horrible things, went “berserk,” and made poly‑phobic comments — she stepped into what’s considered reactive fabrication, a common trait in people who panic when confronted with their own bad behavior. The problem is that she kept contradicting herself. In real life and even in legal cases, changing your story multiple times destroys credibility. Police interviews, therapy notes, and academic research show that consistency is the number one marker of truthful recollection. Her “I don’t remember what you said but if I remembered you calling me a c*nt then you probably said the other stuff too” is basically self‑incrimination disguised as confusion. That’s like saying “the lie I told earlier is true because it fits the narrative I want.”

The gaslighting element is also strong here. Gaslighting doesn’t require saying “you’re crazy.” It can be subtle, like rewriting events to make others doubt their experience. Sally tried to do that with OP’s BIL. And the saddest part? He actually believed her over someone he has known for a decade. That’s how manipulation works — it preys on emotional bonds and guilt.

Let’s shift to an interesting angle: OP telling BIL that “one day she’s gonna get her shit rocked” or get punched by someone less polite. While some people online might clutch their pearls over that, in social dynamics research that’s not considered a threat. It’s a predictive warning — like saying “if you keep cutting people off in traffic, eventually someone’s gonna road‑rage at you.” It’s commentary on risk, not intention. There’s no legal issue here because OP wasn’t threatening harm; she was stating that Sally’s pattern of disrespect and physical boundary violations could lead someone else to react badly. Honestly? It’s true. That kind of behavior can absolutely backfire in real life.

Another important detail: OP vetoing Sally being present at the sit‑down. That was smart. In conflict resolution strategies — especially when discussing harm — you don’t bring the person who caused the harm into the same room with the victim unless it’s mediated by professionals. It’s similar to why restorative justice programs require trained facilitators. OP protecting her boyfriend from sitting in the same room as his harasser isn’t dramatic; it’s standard safety protocol.

And let’s not ignore the relationship‑red‑flag aspect. BIL admitting Sally has lied before, then still getting emotional and defending her, is classic “rose‑colored glasses syndrome.” People often make excuses for new partners because of the honeymoon phase. Eventually he’ll either see the pattern clearly or stay stuck in it. But none of that is OP’s responsibility.

In the end, the updates basically confirmed what OP already knew: Sally was lying, inconsistent, and manipulative, and BIL was caught up in protecting her instead of looking at the facts. OP didn’t escalate, didn’t yell, didn’t attack. She simply stood up for her boyfriend and enforced a boundary. Honestly? Kinda the bare minimum.

Folks were aghast at Sally’s “predatory behavior”, and they all agreed that she needed to apologize to the poster’s boyfriend as well