Shock queen Kathryn Harrison takes her favorite subject — transgressive sex — and spins it into a juicy, if overwrought, upper-middle-class nightmare in Envy. Will Moreland, a 47-year-old NYC shrink still reeling from the death of his young son, finds out he may have fathered his college sweetheart’s grown child. His marriage is foundering and he’s begun fantasizing about his female patients. Enter a naughty 24-year-old grad student, who turns up at his office hoping to be cured of her addiction to seducing — or, as she puts it, ”collecting” — older men (”If they have a little gray hair on their chests, that helps”). You can guess what happens next, but probably not what happens after that. Harrison has some admirably creepy plot twists up her sleeve — and some extremely nasty sex scenes — though she fails to knit them together convincingly.