People over 50 talking about sex and — yikes! — having it! Welcome to It’s Complicated, a romcom that qualifies as a waking nightmare for teens and infantile men whose definition of “hot” hovers around jailbait. Screw them. In this unapologetic chick flick from writer-director Nancy Meyers — she profitably reinvented the genre with What Women Want and Something’s Gotta Give — Meryl Streep plays a divorced mother of three grown children who winds up slutting around with the rat bastard (Alec Baldwin) who divorced her for a younger model (Lake Bell). Streep even has an amiable architect (Steve Martin) sniffing after her. Meyers panders to another popular fem fantasy: conspicuous consumption. Streep’s Jane Adler runs a successful bakery in chichi Santa Barbara, and her home, from kitchen to bathroom, is drooled over by John Toll’s camera. Streep is asked to giggle often, often for no good reason. But the actors are consistently expert. Martin makes his pot-smoking caper with Streep memorably hilarious. And Baldwin, the consummate scene-stealer (wait for his nude shot!), goes comic deviltry one better by adding a touching human dimension. You don’t have to feel guilty for lapping up this froth. Just don’t expect nourishment.