Dilemma

View Quoted Comment He did not molest her.

Sorry that happened to you though.

View Quoted Comment Unclear, here.
Did your invitation say, Aunt K and a plus one. Or, Aunt and guest. Or anything that specifically said, you may bring a guest? If so, she is completely in the wrong, to turn him down because she does not care for him, for no particular reason. If you are given an invitation that specifically says to bring a guest, you choose who. . . .
If the invitation was addressed to Aunt K, nothing else, and you responded 2, myself and a guest familyguy, then you were wrong to assume you could bring a guest. So, which did the invitation say?

Clearly, this is a decision that only you can decide, based on what's more important to you. On the one hand, you've described this man as "a friend for 8 years" and seemingly someone one you chose for a courtesy "plus-one" to a family wedding (so, not a SO that anyone was aware of). And, on the other hand, your niece, the bride, has made it clear she does not want him at her wedding. In that situation, personally, I'd choose any of my nieces over a "friend," and assume they are smart, sensible young women who would have reasons for their request. But, only you can decide for you.

However, I do agree with the PP who suggested just because the niece hasn't confided in you that anything happened that made her not want him at her wedding doesn't necessarily mean nothing happened. Imagine something traumatic happened to you as a child, and for whatever set of reasons, you've chosen to keep it to yourself. Then, because of a set of circumstances you might suddenly have to face the person who hurt you, but saying, "no," raises questions from someone else you love and trust about why you would do that.... And, all this just a few weeks before your wedding. Do you want to share widely/make public info you have kept secret for so long? Do you want to risk opening old wounds and/or creating new ones when all you want to do is focus on your happy future? Probably not. Maybe, as you believe, NOTHING ever happened, but I think PP raises a good point, that you can't know for sure what did or didn't happen. So, if a beloved niece is asking something of you that doesn't make much sense to you, only you can decide if you want to indulge her request or not. I don't envy you, and I do understand this can seem completely unfair and rude to you, so you need to follow your heart. Good luck as you decide how to respond.

View Quoted Comment

This is an "Etiquette and Advice" Forum.

View Quoted Comment Okay, in that case, she’s definitely being rude if she gave you a ya one and is now trying to micromanage who you bring. It’s messed up. It would be fair to change your answer now and say “okay in that case, I’m not coming either” .....but . It’s your niece. So personally, I’d probably be mad and judge my niece a bit , but as the adultier person in the relationship dynamic ... *id* want to be the bigger person and go despite her being rude , because I personally would not want to miss my niece’s wedding as I don’t think that’s a thing our relationship could recover from, and as annoyed as I could be at my niece, I can’t imagine ever feeling okay about missing her wedding. But, that’s my relationship with my own niece, it may not be the same with you guys. She’s absolutely in the wrong, but if the only real course of action is to skip the wedding, that also comes at a cost.

View Quoted Comment I think some brides go too far. If you were given a plus one and she’s saying but not that one, that’s rude. One is not to specify who your date is supposed to be. However, if you are not in a serious relationship or near marriage, I would advise just figuring out a way to uninvited him. She’s you’re niece so you really should go to the wedding. This is not a fair situation. I’m sorry.

I guess I don’t understand why you don’t wanna go alone. She’s your niece, he’s your friend. You’ll have loads of family there, at least that’s what it sounds like. Why are you so intent on bringing him that you’d rather miss the wedding than go alone?

View Quoted Comment Ok not to be rude. i think she gets it. Its odd that the niece does not want the aunts friend there. Its one person. We all get it. Shes asking if she should go or not. No need to keep bringing up that her friend may have done something to the niece. 🙅‍♀️

Is your plus-one a long-term partner (i.e. living together/dating for several years) or someone you recently started dating?

Yeah this is ridiculous - she shouldn't have reneged on a plus one. I'd be annoyed and probably wouldn't attend.