Love this one but runs very very small

I get compliments every time I wear this cardigan, and even my husband said it was a great buy (which says a lot because he’s super picky and rarely gives compliments). The sizing does run quite small, though. I usually wear a size S, but I went with an M for a looser fit, and even the M feels pretty tight. There’s no way I could actually button it up—the buttons are purely decorative at this point. Luckily, I prefer wearing it open, so it’s not a big deal for me. Just something to keep in mind!