Hi Bear,
I've got a 2-part answer, for what it's worth, and I hope some bit of it might help.
Part One:
It sounds as though you have a crush on a bully. Sound odd? In my past I have felt things like that--someone (this was past but I can write better about it if I use present tense) is capricious and hurtful and disrespectful with me and because I was trained to turn the other cheek I overdo it and find I am fascinated, oddly drawn TO rather than repulsed away from, and I'm just as magnetically drawn to their positive traits (the sparkle and charm that draws others, too).
It's almost hypnotic. This person seems to have everything I lack. I can't stop thinking about them. Most especially, this person's lack of empathy means they lack the eternal trigger pain I am lugging around like a sack of rocks. They are careless, reckless, unkind, selfish and greedy...and seem happy and carefree!
Whereas I am kind, patient, empathetic, determined to see what's good and interesting about everyone other than me (including them), respectful and pleasant to others...and I'm NOT happy. Not happy at all.
I have a radiant 18-month-old human here in my arms. And I'm so upset about the photographs/announcement ritual being stolen from me at her birth that I can't really enjoy her in a peaceful way today. I'm holding her, but my heart is elsewhere. I'm with my SIL. I'm really mentally sitting in her living room, wanting to wipe that arrogant smile off my bullying Nsil's face because HOW DARE SHE. And why, why, why wasn't I ready with the potent, powerful, perfect putdown when it all happened.
And why, why, wasn't I tough enough and assertive enough to just tell her off at the time...and around and around and around my mind goes, always circling back to her, and my baby stirs in my arms and I don't really have time to focus on her, I'm ruminating over her birth, my birth moment which was stolen from me, and I look back at my baby being born and the following days, with all the SIL's Nistic appropriations of MY turf, MY moment in the sun, MY right to run certain rituals, and those scenes glow like a movie screen, they are the biggest thing that was happening, and the baby's chatting and moving and I wish she would just go to sleep now, I've got some serious thinking to do about my SIL...
Part 2: (Ignore if it's stupid or off the mark, I often write fantasy monologues/dialogues but never expect they'd ACTUALLY fit. Still, hope it gives you some strength...)
"Dear SIL:
This letter is 18 months late, but I need to write it. I am going to be pretty direct.
I admire you for so many traits: your sparkle, your social charm, your beauty, your X, your Y, etc. Among your talents is your gift for designing attractive announcements and being quick and clever with computer applications. Bravo.
But I have to tell you that I was so hurt and angered by your taking over my role as the happy parent--taking my husband's photographs of the birth without even asking, creating and sending out a birth announcement that was OUR right to do--and generally appropriating and taking over the whole experience.
I felt invaded and invalidated to a degree I can hardly describe. But it was one of the most upsetting things I've ever experienced, and I never want to go through anything like it again. One of the most important days in my life, and you made me feel like a bystander.
Likewise, although we may never choose to be friends, I want to have cordial and peaceful relations with X's wife. You are part of my family. As families often are, we may not have chosen each other as best friends. But whether we are close or not, I want to make clear that I want to be treated with respect.
If you are going to ignore me when I am present, roll your eyes when I speak, and generally treat me dismissively and disrespectfully, then I do not want to spend time with you.
I would rather we could speak to each other with respect and courtesy, and that is how I intend to treat you. But if that can't be reciprocal from now on, I will have to withdraw.
My child is my child, her birth was MY experience, sharing photos and a birth announcement were OUR rituals and rights. And rather than stew about this a day longer, I wanted to tell you how I feel.
Bear"