It's very hard to sit in my dress!

Hello beautiful brides, I've been sewing my wedding dress and am so close to it being finished, but I tried to sit in it and it's very difficult. The hip area is too tight only when seated.
It's a mermaid style, perfectly "snatched" when I'm standing, and the outer structural layer is satin - which has no stretch.
Anyone who bought a satin mermaid (or similar), how did you sit down??? Did your seamstress clue you in to any solutions?If I let out the seams it won't look as fitted, but is this the best fix?The ladies of my lineage blessed me with large hips but the problem is balancing fit vs. sit.