UG Purple Label - Purple Checker Button Up

Almost like new! I’ve actually never worn this out, took off the tags to try which I do sometimes. This is purple checker with pink lining. Oddly enough there is a stain on the back: lower back left (see photo). I’m sure if you wear your shirt tucked in, you can’t see it. Comes from a clean, non-smoking home. Please manage expectations, especially the noted stain which could maybe be washed off? May not? Again, I’ve never worn this out so not sure if I purchased it not knowing?