Ooh read about the Aunt possibly being golden child that poor Mum is used to pleasing, when I read that it all made sense. I'm guessing this lavish bash is a mother/daughter ensemble, the groom is saying if it's about getting married, you know, our lifelong commitment to one another, we could just go down the registry office.
I'm pretty sure Gluezilla has spent many a night being consoled by GlueMum, after packing her bags, bawling, I thought you loved me H2B, why would you do this to me. The most special day of our lives and you'd prefer the registry office. I mean so little to you.
I'm sure we all have that one relative who is the apple of the parents eye, by default they could spawn the son of Satan but he'd be so much better than the other Grandchildren.
I recall a party for a sibling when I was pregnant, I had hyperemesis all the way through (both times) so any period where my body would allow me to feel hungry, I'd want to embrace it. I was so emaciated, it was horrific. Mum had done this buffet, all I wanted was to pinch a sandwich before the nausea returned. I got snapped at for being so rude, as we were waiting for my Grandparents, my Mum had worked hard to create a spread like her sibling would. Yet everyone knew that by comparison, she could have got the Queens cooks to prepare said feast, it would never match what the sibling could achieve.
I remember distinctly having rather sharp words about how the symmetry of the sandwiches made fuck all difference. Was she really going to deny her grandchild to be, an extremely rare opportunity of nutrition. Obviously I would never be the same at another party, although a few months down the line there was another big celebration, other side of the family, my relatives from arrival were asking what could they do to help, if I was hungry help myself or ask someone even if the food wasn't unveiled. They even got ginger beer just for me, which I'd never tried and was apprehensive about, but it did the trick and I stayed till past midnight, plus wasn't sick once. I didn't feel like a fuss was being made, apart from my reluctance to drink anything carbonated, it was all really discrete.
I'm sure the sun shining out of maternal relatives arse scenario, will pass down from generation to generation. I refuse to even acknowledge it, as I know I could have gone on to get a doctorate with University lecturing opportunities, but I'd never be as good as a cousin considerably younger.
There's more stories I could tell but they'd pretty much out me. But OP if what others and myself have said about your Mum and 'Golden Child Aunt' ring true, you're well off not being there, as I'm sure some goady relative, most likely your 'Golden Child Aunt' to be precise, will be comparing your celebrations when you got married, to Gluezilla. Not going you can simply say, 'My DAY, that's right DAY, was about my marriage and vows to my wonderful husband. Anything else was* pretty much redundant for us, mere formalitie*s. We're happy you were able to share the occasion. 'X' years and still going strong!'