What should I wear to the wedding today?

Here’s the deal. Dress one is very sexy, black chiffony material, Empire bodice, tea length, beaded low-cut top. Dress two is two-piece, emerald green, velvety long sleeve tunic top, knife pleated chiffony skirt. Dress one is a tight squeeze; Dress two is very comfortable but frumpier. Weather today is cool, crisp Fall day. Should I go for sexy or comfortable but more frumpy? It is a fancy evening wedding.