Thanks so much for all the help here ladies!! I should clarify that when I say "pucker" it's not actually pulling or small, it's more like what Diana describes in that that the zipper puffs up in back and gives me more volume there than I've already got I'm hoping I'll have time this weekend to pop into Nordies and see what they can do.
Diana, YES short and narrow waist with a extra booty sounds like me too. This is a perpetual problem with dresses >< In this case, the waist width is correct and actually sits at my waist for once! The zipper bias is definitely stiff.
Diane, yes the pattern is quite dense there so the seam could work and honestly if that's the only solution I think I would be OK with it. Since the dress is a more loosely tailored fit, getting in and out should still work with a shorter but not excessively short zipper. I like the idea of taking a printout of the blog post with me, I'll definitely do that.