Gray and maroon Desigual dress

this is BNWOT and it is only missing the belt. it's by Desigual and it's cotton and slips over. it does stretch but there is no tag size listed on the dress. I think it fits like a medium bc I've never worn it and it's too small for me. in perfect shape besides missing the belt. but the loop holes on side of dress are so small it's hardly noticable that it even has a belt.