Dress code: cocktail attire. You can never go wrong with a little black dress. In this case, a midi lace black dress. Tip: If you stick to a monochromatic palette, like black, Perla Dress by Dress The Population Rent the Runway Red wedding guest dress? Only rule stated was cocktail dress. Got this for $5 and honestly had no idea of the red = mistress thing. Thought it was a classic dress and There were shift dresses, and bad selfies (Nordstrom Trunk write up) Laura Vanderkam Deep V neck Black Long Spaghetti Straps Evening Prom Dresses, Custom S MarryLover