Naked City Covering The Bases Some shockingly savvy private-school girls on the sexual politics of hooking up, getting and giving pleasure, and parents who are too hip. By Amy Sohn Nell and Cara are 14-year-old freshmen at a private Manhattan high school, and as I sit down for coffee with them, I am chagrined to find we are wearing exactly the same brands. “Is your watch Red Monkey?” asks Cara, who has a goofy smile and silky brown hair, grabbing my wrist. “So’s mine!” She raises her arm next to mine like we’re Wonder Twins. I notice that Cara’s best...