black dress with ruffle bottom Final Sale Plus Size Button in length voluminous ruffle skirt Black One Shoulder Diagonal Ruffle

With a zip up back closure, this dress offers a loose and relaxed fit in a straight line silhouette, made with a blend of 88% viscose and 12% nylon for a soft and comfortable wear

Look like a fairy-tale Princess in this 3D floral applique long sleeve wedding dress with A-line skirt from Ladivine by Cinderella Divine CDS436W

White and Black Polka Dot Long Sequin Birthday Prom Dress (1Y392) $270.75 USD (free shipping) Made to order, customizable

A crepe mini-length underlayer

Just make sure your look falls in line with black-tie criteria, can hold its own next to fancier black-tie options in pictures and is also considerate of the event and host.