There is an unforgettable scene towards the end of Leo McCarey’s screwball-comedy masterpiece The Awful Truth where the female lead, Lucy (Irene Dunn), is attempting to sabotage the relationship between Jerry (Cary Grant), her recent ex-husband, and Barbara (Molly Lamont), his new fiance. Lucy embarrasses Jerry deeply by showing up at Barbara’s house and pretending to be “Lola,” his drunken floozy of a sister (who does not exist in reality). In front of Barbara and her stuffy parents, Jerry has no choice but to go along with this ruse. Only the longer Lucy sticks around “in character,” the more obvious it becomes that Jerry actually appreciates the cleverness of her act. His exasperation slowly, almost imperceptibly, turns into admiration. As Lucy/Lola sings “My Dreams are Gone with the Wind,” to demonstrate her risque-circa-1937 nightclub routine, Jerry starts to smile in spite of himself, an indication that maybe these two nutcases really do belong together after all. Toni Erdmann, the third feature from the young German filmmaker Maren Ade (Everyone Else), is like this one great scene stretched to an epic running time of two hours and forty two minutes — and I mean that as a huge compliment. The film may be leisurely paced, especially for a comedy, but when the climactic, instant-classic “nude party scene” arrives, you know that Ade needed every one of those minutes in order to reach her sublime destination.