Not sure if one more opinion is useful, as it is only that, and a humble one at best.
At first reading your post
@Soconfused7468 I would have said, of course it is necessary to disclose (if you are able) because it was not your fault and you are not defined by others wrong actions nor your response to them and you're talking about long-term commitment and challenges (and joy, hopefully).
But then I also thought, that is based on 'me'- I would feel empathy and not minimize. But neither would I share a partner's details with anyone else nor treat them with pity. As I see it as an act of bravery. I think in terms of marriage it would also be an influencing 3rd entity that would arise silently. But as
@Movingforward10 said Idk what she is like.
However, you also express what sounds like re-enactment (totally normally btw). My experience (more than opinion) is that that is potentially disastrous for the long term, especially if you heal. Simply because (IMHO only) re-enacting what you yourself described as 'warped' and that caused/ causes you great shame and made you feel like a laughing stock, is bound to be very difficult to dis-entagle from a current (hopefully healthy) relationship with your partner. Projecting on them the feelings you had towards your mother may paint them in the wrong light. At worst it also won't manage to heal the feelings you had when it occurred. In many ways I feel it's (our) attempt to heal it, or self-minimization (avoidance) by means of repetition. By analogy, a person who is raped or abused ending up with re-enacting rape or abuse (or shame) while in the Driver's seat, so to speak. So yes familiar, but rarely produces the desired end of self and other healthy love. (Not saying it might not for others, just me experience. My choices in that vein much younger personally didn't end well).
Not to say also, but you might want to consider it, but healing away from it might be facilitated by the fact your fiancee is not your mother, and wouldn't want to shame you or punish you or demean you. (Hopefully) she and the relationship is safe (even if not familiar) for the very opposite reasons. And to recognize when you feel like she is punishing you, but she isn't; that is due to fearing it after your experiences and how it colors your perspective (fear).
I agree with
@arfie to go with your gut and heart. I cannot imagine wanting to be married to someone I had to hide everything core or impactful from, nor they from me, but I also know I'm an oddball in considering such disclosures pretty sacred. I also know I can't imagine disclosing a lot. But then again trust to me is something I have to choose and constantly remind myself of the moment why I knew it was right to choose, and not be misled by fears and doubt. (There is much fear choosing that, for me anyway.)
Only you know what's best for you. Your relationship made it this far for a reason, and likely based on the fact she doesn't see you as you might see yourself after your mother's actions. That is not because you haven't disclosed but rather because you are not as your mother's actions made you feel. You are not laughable and most definitely shouldn't have to feel shame-filled. Wounded is not laughable or damaged. Nor are your desires weird in particular considering what you have suffered. And all children start by wanting to be loved, especially by their mother. Also hard if you both loved her and depended on her, but equally suffered greatly, or your greatest initial sufferings, at her hands.
Maybe there is a better way ahead, that reduces or eliminates much of the anxiety and depression too that isn't either/or.
Welcome to you. Best wishes.
