These are gorgeous and seem to be high-quality but it takes a while to get your head around the sizing. Between Rebel Romance and Run and Fly, there seems to be a variety of models who wear the same high street size but different dungaree sizes, and none of it matches up with my experience. I wear a high street size 8 and have a pair in another design in 3XS, which I kept because it's meant to be worn in a relaxed fit, but after a few wears I'm realising it's uncomfortably wide and there's way too much fabric between my legs.
I got these in 4XS and they're borderline too tight! I'm keeping them because they're really beautiful and I suspect they'll relax over time.