There is mixed feedback about the sizing of this garment.
I'm 5'9, my waist is 31". Im a slim/medium build.
I have looked at the sizing guide which would put me in a Small... but everyone says buy a size up, should I go for Medium?
I'm 5-9" 33"waist 39/40chest, fits snug, not tight, no flapping, medium, I'd go by your chest size