Posh parties. If you move in fancy-pants circles on the regs, you're probably a pro at reading between the dress-code lines. But throw a novice in the mix, like a mate you're persuading (bribing?) to come with you, and the chances are your plus one is screwing about what to wear right about now. Luckily, Sistine Rose Stallone (yes, Sly's daughter) offers up all the answers, via this one dress.