At the recent anniversary event for Gucci's Chime for Change, Blake Lively went for equal parts demure and dainty, and sultry and sexy. On one hand, her Gucci Fall/Winter 2014 frock featured a fit and flare silhouette and conservative sleeves. On the other, it also had a deep keyhole neckline that showed an ample amount of skin.

(Photo sources: Fabsugar via POPSUGAR Fashion, and Vogue UK via British Vogue, all on Pinterest)