Denim button up, tail coat back blouse

Light weight grey denim button up blouse. The back is longer that looks like a tail coat. Worn handful of times still good condition. Fits a little larger than size shown prob fits S-M), it's looser. (P.S. sorry its wrinkled, nothing is wrong with it, my closet is full and my clothes are bunched up which is why I need to get rid of a lot of clothes)