If you want it, you got it. A surfeit of sex jokes, that is. Maybe adolescents want it, for this Ivan Reitman turkey, My Super Ex-Girlfriend (2006), IS an adolescent film. (It also moves at a rather leaden pace.) In fact, the two principal females, played by Uma Thurman and Anna Faris, are easy lays. That’s right, both of them. We have something scurrilously demented here.