SOLD OUTSIDE POSH- -Sophisticated and classy evening dress

I can’t express how classy and sophisticated and beautiful this dress is in person. Wore it once at an event. gained some weight and unfortunately won’t fit in it any more and it does not stretch. I believe the slit in the back can be opened more, I’m not sure if I closed it a little bit or if it was that way and I just did not not open it. I may have removed the size tag because it was itchy.