Sisters Sarah (Lizzy Caplan) and Beth (Alison Brie) are in relationships with bandmates Andrew (Martin Starr) and Kevin (Geoffrey Arend). Beth is making plans for her wedding with Andrew. Sarah, an artist, moves in with Kevin but struggles to overcome her ambivalence. At a performance by Kevin, Sarah is approached by Jonathan (Mark Webber (actor)), who has a crush on her and has been hanging around the bookstore she manages. He decides to approach her but withdraws when he overhears she's living with Kevin. Kevin, ignoring warnings from Andrew, proposes to Sarah from the stage. Overwhelmed, she moves out and gets her own apartment. She talks to Jonathan at the bookstore and a new relationship blossoms. Beth, in the meantime, has become obsessive about her upcoming wedding plans, causing friction with Andrew and Sarah. Sarah feels isolated when she discovers she's pregnant and pulls away from Jonathan without explanation. She eventually tells Beth, who seems to take it as an attempt to ruin her wedding plans. At this point Sarah has a first solo show of her work. Andrew, Kevin, and Jonathan all attend, but Beth doesn't. The opening at the gallery acts as a catalyst, and all things come to a head. Andrew gets angry at Beth for not showing up at gallery. He wakes to find a note from Beth who is waiting for him at the synagogue. Meanwhile, Kevin shows up at Sarahs apartment and wants to date her again. Sarah rejects him saying that she is pregnant and the child is not his. The next day Kevin beats up Jonathan at his aquarium, but later apologizes and tells him everything. Beth and Andrew postpone their wedding. Sarah visits the hospital to get an abortion. Beth meets Sarah over there and Sarah decides to drop the idea. When Sarah reaches home she finds Jonathan with her cat who was missing. She kisses him and the movie ends with Sarah saying "Jonathan".