No need for undergarments in this dress - they are built in!!! Wearing a 2X in this one, you may need a friend to get it on but absolutely love it! So flattering + supportive! Love the shapewear inside! I wear the XXL in the blazer! Plus size fashion, occasion dresses, wedding guest dress, what to wear wedding, formal event outfit idea, fall fashion, early fall outfit ideas, midsize dresses, midsize fashion LTKSeasonal LTKNYFW LTKWedding