Many of Hollywood's biggest stars stepped out onto the red carpet this week in risqué black dresses.Lindsay Lohan, Halsey and Brooks Nader are just three of the big names who dared to bare in revealing dresses this week, whether it be in sheer looks or one with a high slit.Here's a look at some of the stars in little black numbers.SYDNEY SWEENEY STUNS IN CUT-OUT DRESS WHILE MICHELLE MONAGHAN TURNS HEADS IN LEATHER: PHOTOSLindsay Lohan turned hea…