This seems like such a boring topic, whom to invite to a wedding, but I didn't see it addressed in the directory, and these are extraordinary circumstances, so hopefully you'll be able to offer some advice.
I am the oldest of three girls. Ten years ago, during my middle sister's freshman year of college (let's call her Jane), my aunt's husband had business in Jane's college town. He took her out to dinner; she had a few drinks, then a few more. Jane blacked out. She woke up the next morning in his hotel room, naked. He was in the shower. Both sides of the queen bed had obviously been slept in. Inappropriate, definitely; sexual? Only the husband knows, and he's never talked.
The family was split. Mom not wanting to take sides. Sisters obviously all together. Grandma on aunt's family's side. Aunt doesn't know, or at least never mentioned it and is still married. Of course, in healthy-family fashion, no one has ever openly discussed what happened and the wounds are still there. The sisters all moved away and the extended family that was never close drifted further apart.
Fast-forward to the youngest sister's wedding, let's call her Sally. Sally invited her aunt and the husband in question to her wedding, assuming that they would never come. They responded "with pleasure."
Now what to do -- can Sally revoke the invitation? It would incite huge family drama. Mom thinks Jane should be over it by now. Grandma never believed Jane in the first place. Jane isn't over it, and yet, in a way, she is. She doesn't think about it, she's moved on, but still. She doesn't want to see him. None of us do. What if Sally disinvites him and for once we can, as a family, address some of those skeletons? Or are we overreacting? It is just one day, and there will be a lot of people there, and they might not end up coming.
I'm hopeful that someone outside the family can help us figure out what to do.
Not Yet Over It/Conflicted
What I suggest you do is deal with these two matters separately. The wedding has given rise to memories of this old event, but I don't think disinviting the uncle and aunt would solve anything. Have the wedding as planned. The family has danced gingerly around this issue for a decade; they can do a little more dancing at the wedding. I suggest you dance as well, although not with the uncle. In fact, try to be intoxicated by the joy of the event, and pay as little attention as possible to the uncle. Be aware of where he is so you can be elsewhere. Try not to be in family photos or in dance circles with him. Forget that he's there so you can enjoy your sister's big day. It may help to discuss a game plan with your sisters beforehand, so you can help each other avoid awkward situations.
After the wedding, though, I strongly suggest that whoever is still troubled by this event seek earnestly to understand how it continues to reverberate throughout his or her life and throughout the family. The person most likely to want that understanding is your sister, to whom it happened. But all of you seem to have been affected to some degree, so others may wish to seek this understanding as well. There are many ways to go about this. So many books have been written about family systems and how they operate that I can hardly say where to begin. You can find these books at a library or bookstore. I also suggest you consult a therapist who specializes in family troubles. Say, "I am troubled by this event. I want your help in understanding how and why it continues to affect my life."
Many things remain unclear. Your sister may or may not have had sex with your aunt's husband. Your uncle may or may not have raped, or taken advantage of, your sister. Someone in the family may or may not have told the aunt about it. The uncle and aunt may or may not have discussed this between them. We do not know.
Because so much is unknown, getting over it may involve not only trying to understand what happened, but accepting the unknown itself as a phenomenon -- the murkiness of the past, the unreliability of our own memories and our own beliefs. Facing the unknowability of the past may result in feelings of profound regret -- I should have done this or that! Why was I paralyzed with fear? I should have acted! I should have protected my sister or daughter! I should have confronted that man!
You cannot change a whole family all at once. Each individual has to change his own behavior within the family. This need not be done alone, however. If the three sisters are united in their outlook, they together might seek a facilitator or therapist to work with as a group. They might need to say things to each other, or hear each other say things, in order to be at peace with what happened. There may be feelings of failure to protect, betrayal, letdown, anger, all kinds of things they feel guilty about feeling, but which ought to be acknowledged so they can move on.
There is also the question of what to do about the uncle. The problem is that it is unclear what happened. It was clearly, as you say, inappropriate. Was a crime committed? No one knows. All I know is that feelings of rage and bitterness are likely to persist. Perhaps the middle sister needs to confront him directly. I don't know. Those are questions to be answered through difficult struggle and wise counsel.
So much has been said and written about "dysfunctional" families that it is helpful to remember what we actually mean when we say that. To me, it means that when troubling issues arise, secrets are kept, lies are told or believed to be told, and certain people are scapegoated or labeled as a way of avoiding the truth.
Bad things happen in dysfunctional families. Avoiding the truth doesn't just impede people's personal emotional growth and whatnot; it has real-world consequences. When people can't talk about certain things, practical information does not get through. Since no one talks about sex in the family, perhaps the sister did not know it was dangerous to accompany her uncle in a drunken state to his hotel room. Perhaps she did not know that she should immediately get herself to a clinic to find out if she had been drugged and raped. Perhaps the uncle lives a life of secret deviance to this day, and no one talks about it. We really don't know what he's been up to all these years. No one talks about it. Everyone keeps secrets.
As you said yourself, to deal with this matter you need someone "outside the family." I hope I can do my part by directing you to useful information on family systems, and to a therapist.
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