By: Addison Wylie If Rob Cohen’s The Boy Next Door is an indication of anything, it’s that American filmmakers are still having grave difficulty making erotic thrillers without avoiding camp.  Nowadays, it’s almost a requirement for the movie to fly off the rails. A film like The Boy Next Door often has the viewer questioning if the filmmakers were making a bad movie on purpose.  A movie gullible audiences could innocently flock to and get…