Backless Asymmetrical-Neck Long Prom DressSet the stage in this long prom dress by La Femme. The beautiful backless dress features double spaghetti straps that grace the shoulders before crossing the back in a strappy detail that supports and adds style. For the fashion lover with an edge, the neckline fits asymmetrically with an up to the minute look. The waistline on the long formal dress dips alluringly in a v shape in back, while a side slit opens high on the thigh with every step. Stun