In the market for a hot tip? Here's one: Don't bang your best friend's little sister. Especially when she's an investigative journalist and your investment company is the target of her latest scoop. Unfortunately, I have a thing for high-risk bets, and Ellie's suggestion that we mix business with pleasure is too sweet a deal to pass up. F riends with benefits is the kind of low stress romantic situation a busy New Yorker actually has time for. But...