I have found w/ all of these lines that say go down a size that it depends on the style of the pant and your own body shape. For example, tried 4 different NYDJ and two of them fit going down a size and two of them were so tight they were like poor fitting leggings (which is not a look I like). Same w/ Belle's jeans, totally hit or miss on good sizing and fit.
For reference, I have a slim build, but do have a round tush. The pants that were tight were tight EVERYWHERE. Yes, I could get them on and even get buttoned and zipped. But I have a phrase w/ pants --- just because you can, doesn't mean you should.
Good luck. IMO, jeans and bathing suits are the worst to try on and find good fits.
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