NEW YORK — Lounging around looking sexy may not be an Olympic sport, but that hasn’t kept lingerie designers from finding a little inspiration in an activity that is — ice-skating. This season, they’re transforming little nightgowns and short robes into flirty confections that recall the costumes Sonja Henie wore when she single-axled her way into sports and movie history. Here, Roberto Cavalli’s spotted, feathered and boned silk robe. Sergio Rossi shoes. For more on intimates, see pages 19 to 25.