Lena Dunham suddenly finds herself an enemy of her people. This week, the creator and star of HBO’s Girls, who is Jewish, wrote a humor piece in The New Yorker called “Dog or Jewish Boyfriend? A Quiz.” It begins: “Do the following statements refer to (a) my dog or (b) my Jewish boyfriend?” and offers, to test one’s dog-or-Jew acumen, statements like, “doesn’t tip,” “has hair all over his body, like most males who share his background,” and “comes from a culture in which mothers focus every ounce of their attention on their offspring.” Cheap?