'AITA for refusing to promise my best friend that I wouldn’t sleep with a mutual friend?' UPDATED

"AITA for refusing to promise my best friend 100% that I wouldn’t sleep with a mutual friend?"

I (30F) have a best friend (29F) of 13 years. She is in a long-term committed relationship (7+ years) and lives with her partner. We also share a mutual friend, “A” (30M). About 8 years ago, my friend and A had a brief situationship. They slept together once and then tried to date very briefly long-distance, but it ended because he did not want to pursue anything further.

She was upset at the time, and it never became a mutual relationship. After that, they stayed friendly for a while, then lost touch for several years, and reconnected as friends about a year ago. There has been nothing romantic between them since. Recently, A broke up with his long-term girlfriend.

Before that happened, my friend and I had already planned a trip to visit him together, which we have done before. This time, we were planning to stay at his place instead of a hotel. After his breakup, my friend started making comments like “haha just please don’t sleep with each other.” It was framed as a joke, but it was clear she was anxious. I asked her directly if something was bothering her.

I told her two things clearly: 1. I was not planning to sleep with him. 2. I was not comfortable promising 100% that I would not, because I do not like my potential or hypothetical relationships being policed, and I did not feel okay making absolute promises about future situations just to manage someone else’s anxiety.

I was not trying to be evasive. I was trying to be honest while also setting a boundary. The next day, I reiterated that I was still not planning to sleep with him. Her response was essentially that she was canceling the trip. She said she was canceling because the uncertainty made her anxious and she needed to take care of herself.

From my perspective, this felt like my word was not trusted unless I gave a 100% guarantee, and when I did not, the entire plan was shut down. I understand that anxiety is real, but it also feels unfair to expect me to give up autonomy or make absolute promises about hypothetical scenarios, especially when nothing inappropriate had happened and the history in question was many years ago.

She did not clearly say what she expected me to do differently. She canceled the trip without further discussion. I feel like I was honest, respectful, and that my boundary was reasonable. AITA for refusing to promise 100% that I wouldn’t sleep with him, even though I said I wasn’t planning to?

TL;DR: Best friend wanted a 100% promise that I wouldn’t sleep with a mutual friend she had a brief, one-sided situation with 8 years ago. I said I wasn’t planning to, but did not want to make an absolute promise. She canceled a planned trip because of the uncertainty. AITA?

EDIT: Additional context people asked for. A few clarifications that seem important for understanding my response: 1. This was not limited to this specific trip. My friend told me she did not want me to hook up with A at all, not now and not in the future. She also said she would be uncomfortable with me having any kind of romantic relationship with him, not just intimacy.

2. Many people asked why I couldn’t “just say sure, no problem, I won’t do it.” The reason is that this was not framed as a one-time reassurance about this trip, but as a blanket expectation about my relationships going forward. I was being asked to promise that I would not pursue anything with A at all, indefinitely.

My response (“I’m not planning to, but I’m not comfortable with my relationships being p*liced”) was intentional. There is prior context where my friend has tried to restrict my relationships based on her feelings, even when nothing was actively happening, which is why agreeing to a blanket promise felt important to push back on.

In one case during university, I was starting to talk to a guy we both knew. She asked me not to pursue anything because she wanted to keep him “as an option.” I agreed and stepped back. She later started dating him about two years after that, and they are still together.

In another case, she stopped speaking to me for about two months over a guy she had liked years earlier in school, even though nothing had happened between them and I explicitly asked if she wanted me to stay away. I was told “do whatever you want” and then ignored. After over a week of no communication, I eventually dated him.

That relationship later became my long-term relationship and engagement. Because of this history, I did not feel comfortable agreeing to a promise that would restrict my relationships in general, even though I was clear that I was not planning to pursue anything. 3. My friend’s partner is aware that she and A had a brief situation many years ago.

He is under the impression that this is long over and not an issue. Because of that, he has been okay with her staying in touch with A and with us traveling to his city. These visits have never involved the two of them alone.

Every time she visited A, I was also there, except for one occasion when his girlfriend was present the entire time. There has been no one-on-one time between them since they reconnected. This is why the request for a 100% promise felt like an escalation rather than a simple reassurance.

Here's what people had to say to OP:

Quietaccident3310 wrote:

NTA. Also, you did say she was in her own long term relationship but still cares about what her friend does with an OLD situationship. Thats just strange to me. I don’t wanna accuse anyone of feeling any type of way but maybe her boyfriend should also feel a type of way about her seeing this friend.

Edit: imagine what she’s gonna tell her BF tho. That she canceled the trip to go see her friend with her friend because she’ll get jealous or feel possessive ? Lol

OP responded:

No, I’ve only slept with my ex in our long term relationship that just ended and before that in the uni I mostly cared to party and do fun staff (not sex though, I was very prudish about my v card) and didn’t really care for dates or relationships tbh so I don’t have a history of dating at all. Then I met my ex and he became the love of my life for the next 9 years before the war related staff has broken us apart.

Flat-Replacement4828 wrote:

Info: was she saying she NEVER wanted y'all to hook up, or just on this trip while she's right there?

OP responded:

Never. I feel like it’s not about hooking up only (although it was her only point) but the potential of us getting into any sort of relationship as there was an attraction from his side years ago but I was in a relationship and didn’t reciprocate.

Now that we are both single she might be threatened by the potential of us getting together eventually which she cannot accept and which makes me really confused as, like said in the post, she is in a long term stable relationship herself.

Captain_Pickles_1988 wrote:

NAH, you are technically correct but honestly what is the purpose of pointing it out. It is similar to my wife asking me if will be home later and me responding that I plan to do so but never know what could happen and don’t want to make absolute promises if something happens to take me away from home.

Obviously everyone knows this is true but it is needless to point out You are not an AH because you technically aren’t wrong and she is being too anxious. It is NAH because of your needless point.

OP responded:

She has a history of policing my relationships, I just wanted to set a boundary. Like, “no, I am not planning on hooking up with him but I also don’t want you to tell me if I can do it or not."

hahaz13 wrote:

NTA.

She’s still not over this guy and claims possession despite being in another long term relationship. Rip your friend's BF though.

Aidyn_the_grey wrote:

NTA. Tbh it's a red flag your friend would get so worked up over this when they are already in a committed relationship. If I was the SO, I would be PISSED to find out my partner is anxious about a friend potentially sleeping with another.

Not long after posting, OP shared an update:

UPDATE: We talked again. She said she panicked because she interpreted our previous conversation as me “preparing the ground” to hook up with him and reacted to that fear rather than anything that had actually happened. She framed it as a misunderstanding.

What’s important for context is that by that point I had already said multiple times that I am not planning to sleep with him. I reiterated this again very clearly during this conversation. Nothing has happened, I’m not being sneaky, and this was never something I was actively pursuing. After that, the trip was back on.

That said, I’m still left feeling pretty uncomfortable about how this played out. Not because I want him, but because I don’t understand why I had to repeatedly convince someone that nothing will ever happen when there were no concrete grounds to suspect that it would, other than the fact that we are both single now. I am also still not okay with my relationships being policed in principle.

This is not about this specific person. It is about the expectation that I should provide guarantees or reassurance indefinitely to manage someone else’s anxiety, which I do not think is normal or healthy between adults. We agreed to put the broader conversation about boundaries and control on hold for now and deal with it later. The trip is back on.

Because many people asked, I am not planning to go to her partner about this at this point. Nothing concrete has happened, and while I have my own thoughts about why she reacted the way she did, those are still subjective interpretations. I do not think it is my place to escalate things or put ideas in his head when no clear lines have been crossed.

My plan is to see how things actually play out this weekend and then, afterward, have an honest conversation with her as a friend about why this situation affected her so strongly, especially given that their history was eight years ago and she is in a committed relationship now. Wish us all luck. I will update everyone after the weekend.

Here's what people had to say in response to OP's update:

supercherryblossoms wrote:

YTA. Sometimes its not about current feelings your friend has for an ex but the feelings surrounding the break-up or relationship overall. My best friend has an ex that we all still talk to, but we all know is off limits, even though she's now very happily married. She was never even truly in love with the guy, but that break-up left a lot of unresolved issues that she had to get over in therapy.

They weren't together long at all, but we know how much the situation hurt her for whatever reason. She definitely never wants him back nor does she love him, but it was a pivotal point for her and it would definitely bring up a lot of old painful memories if he were suddenly involved with one of us and regularly back in the circle.

Not all issues around former relationships are about still being in love with someone. Sometimes its just about the pain that a situation caused your friend and not wanting those memories to be present in your friendship. Unless you don't want to be friends with this person anymore, just find a different guy.

DorianCramer wrote:

You’re overexplaining. Either you have no potential attraction to “A” and you can just tell your friend that, or you do have potential attraction to “A” and you should tell her that you cannot promise not to follow through on that.

Whether you make that promise or not, she has made it clear your friendship will end if you hook up with this guy. That is unreasonable of her since she is with someone else in a long-term relationship but that is her stance. If the opportunity does present itself with “A” it’s up to you to decide whether that sacrifice is worth it. NTA but it’s a lot simpler than you’re making it out to be.

Pristine-Acces6164 wrote:

Out of sheer respect for any and all of my friends’ feelings, my general rule of thumb is that if any of my friends have slept with or had feelings for a guy, he is off limits forever. I don’t care how long it’s been. I don’t care if they’re in new relationships. That person is off limits. I do value my friend’s feelings more than a hookup.

I understand not wanting to feel policed. Trust me, I’m very much an “if I want to do something, I will.” But this is simply your feelings versus her feelings, and this, to me, doesn’t feel like a difficult decision. Is it worth permanently damaging your 13-year friendship for a hookup?