A dress designer tries to break her sister's engagement to a free-living artist, only to discover the man is falling for her instead.

Irene Agnew and her meek fiancé, Waldo Beaver, are learning acting techniques from Bohemian Charlie Lodge, a painter and supposed director with whom they would like to go to Hollywood. Irene's domineering sister Margit doesn't know that she and Waldo have been staying out all night in Charlie's trailer, and is shocked when she finds out. Margit, who spends all of her time attending to business, likes to have everything go according to her own plans and Irene and Waldo's rebellionusness upsets her. She decides to confront Charlie, but becomes frustrated by his unconventional attitudes. Because Irene has lied to her sister and said that she now loves Charlie instead of Waldo, who lacks "yumph," Margit tries to bribe Charlie, whom she is convinced is a phony, to get him out of their lives. She asks her butler Keough, a former policeman and avid amateur detective, to learn everything about him, but in the meantime, agrees to let Charlie paint her, hoping that she can talk him into dropping Irene. In order to do a proper job, Charlie suggest that he and Margit take his trailer to a remote location and spend time alone while he paints her. On their trip, Margit becomes attracted to Charlie's unconventional ways, but fights the feeling and soon drives back to the city. At home, while Margit tells Irene and Waldo that they should be married as soon as possible, Keough tells Margit that Charlie's ex-wife Claire is in town, and Mrs. Kensington-Bly, Margit's financial backer, reveals that Charlie was once her guide in Paris. Charlie visits Mrs. Kensington-Bly and shocks her by inviting her to his wedding in the trailer at three that afternoon to Margit. He then tells Waldo that he is marrying Irene at three. Waldo, who tells Irene that he understands why she prefers a man like Charlie over a man like him, passionately kisses Irene goodbye, then asks Keough for some of Margit's "medicinal" alcohol because he is a very sick man. Meanwhile, Margit visits Claire and learns that she divorced Charlie because her money got in the way of their happiness. She advises Margit not to try and change Charlie and surprises her by saying that Charlie invited her to his wedding that afternoon. As three o'clock approaches, Margit goes to see Charlie, followed by Irene and several of Charlie's pals from the bar across the parking lot. Margit agrees to give Irene her blessing to marry Charlie and soon the Reverend Dr. Blynn arrives to conduct the ceremony. With a band outside waiting to play wedding music, hundreds of spectators are soon attracted and the trailer begins to overflow with visitors. During the ceremony, Irene and Waldo both say "no," when Dr. Blynn asks them if they take each other as husband and wife and Margit and Waldo begin to argue. Soon Waldo, full of yumph as well as liquor, arrives and carries the happy Irene away, leaving Margit finally able to admit to the delighted Charlie that she loves him even though he has turned her world upside down. Overcrowding soon begins to take its toll on the spectators, and a number of fights break out both inside and outside the trailer. Margit and Charlie eventually fall side by side, and just as they are about to get up, the commotion shakes the trailer and causes an Oscar statuette to fall on Margit and Charlie, knocking them unconscious in each other's arms.