Michael Bluth convinces his mother to throw what she thinks is a Valentine's Day party, but is, in fact, a party to celebrate the anniversary of Tobias and Lindsay. In attendance is G.O.B.'s girlfriend Marta, who is impressed by the romantic side of Michael when she finds out he's responsible for the party. Like his father, George Michael is also harboring a secret crush, on his cousin. He searches for a sign using the messages stamped on candy hearts. After some digging, he finds one that reads "Maybe Tonight" and considers that to be a sign. He shows it to Maeby, who grabs it and chucks it at Tobias' head. When he turns around, he sees George Michael standing there by himself. And Lucille, still trying to break up the relationship between Buster and Lucille Austero, sets up Lucille with Carl Weathers, who is there as Tobias's acting coach, on a night Buster has class. Michael gives a stirring toast to each couple and to love in general, and that's when Marta realizes that Michael is the one she should be with, not G.O.B. The next morning, Lindsay says the party finally woke her up. She needs a divorce. Tobias's Never Nude affliction is too much of a burden to bear.
Meanwhile, G.O.B. thinks Marta is cheating on him with a man named Hermano after overhearing her on the phone talking to her mother. What he doesn't realize is that "hermano" is the Spanish word for brother, and Marta was actually talking about Michael. But neither Michael nor G.O.B. realize this, and the two agree to work together to find Hermano. In other love news, Lindsay breaks the news that she and George Michael will be switching roommates. He'll be bunking with Tobias now, and she with Maeby. George Michael fears that this is because Tobias saw the Maybe Tonight candy heart and figured out his cousin crush. Buster, finally fed up with Lucille's nagging, decides to move out of his mother's place, but when he knocks on Lucille 2's door, Carl Weathers answers. Lucille 2 doesn't want to be Buster's substitute mother, so she doesn't allow him to move in. But Lucille, hurt by Buster's attempt to move out, refuses to let him move back. Michael follows Marta around all day in an effort to track down the mysterious "Hermano." Visiting the set of her show, he asks around for Hermano and gets directed back and forth between two brothers. Elsewhere, Lucille visits George Sr. in prison for some advice. Seems that with Buster moving out, she's living alone for the first time ever and she's a little nervous. George Sr., who has just released a self-help video about his learning experiences in prison, advises her to learn to find happiness in being alone.
Having nowhere else to go, Buster arrives at the model home, where Tobias is expressing excitement about his audition for a part in a movie as "Frightened Inmate #2." Marta drops by, and Buster immediately falls in love with her. Michael, who had been following Marta, arrives shortly after, and is surprised to see both Buster and Marta. Michael agrees to let Buster stay with him for a while, but since there's no more room, they'll have to share a bed. And Marta asks Michael if they can go out to dinner to have a talk. G.O.B., who has also been tailing Marta, calls Michael from outside the house, and Michael agrees to get to the bottom of the Hermano situation over dinner. Upstairs, Lindsay confesses to Maeby that she and Tobias are having trouble. In the next room, Tobias confesses to George Michael that he hasn't made love to Lindsay in years. He also mentions that they couldn't conceive, which makes George Michael wonder if Maeby isn't a blood relative. But before he can ask Tobias about it, Carl Weathers calls to tell him that he had gotten the role he auditioned for. At dinner at Marta's home, Marta and Michael talk at cross purposes: she alludes to her attraction to Michael, while he implies that he "knows" she's cheating on G.O.B. When Marta steps away for a moment, Michael asks her son if Marta loves Hermano. The son confirms that she does, and tells Michael that he's sleeping in the next room. Michael calls out Marta for her affair and, taken aback, she asks him to leave. Then he notices a gift he had seen her buy while following her around the day before. It is a tuxedo with a note addressed to him. Realizing he did something wrong, Michael asks Marta's son what hermano means, and finally realizes that, in fact, he was the very man he had been looking for.