When Whitney and Alex, a happily unmarried couple, attend one of their friends' weddings, Whitney realizes that she and Alex are dangerously close to relationship boredom after three years together. Determined not to let that happen, Whitney consults her close circle of opinionated girlfriends Lily and Roxanne. Snapping into action she tries to seduce Alex in a sexy costume, but someone winds up in the emergency room.
After an argument over whether or not Alex uses a condescending "tone," Whitney decides she is going to catch her boyfriend in the act and enlists Mark's help. The two scheme to set up a hidden camera in the couple's apartment. Lily, Roxanne and Neal gather around the television to watch the drama unfold. Later, Alex's brother Brian crashes on the couch, and old sibling rivalries come to the surface causing the two brothers to brawl.
When Alex encourages Mark to recycle his beer can, Mark takes an unusually firm stance against it, causing the two to "break-up." Trying to cheer Alex up, Whitney steps in for guy's night out, only to run into Mark and his new best friend, Neal. In an effort to reunite the bro-mance, Whitney, following advice from Lily and Roxanne, arms herself with some Rocky Road and red wine and sets out to discover the real root of Mark's heartbreak.
When Whitney and Alex go on a double date with Roxanne, Whitney is surprised to learn that Alex had a full life before he met her. In an effort to do more things together, they decide to play a friendly game of basketball, but things go awry and a sore loser emerges shocking the gang. Meanwhile, Lily thinks that she will win Neal's mother over by embracing his Indian heritage, but she takes it to a whole other level.
When Alex's childhood dog passes away, Whitney suggests they adopt a dog together. However, the adoption process isn't as easy as they'd hoped especially when dealing with pound owner Mrs. Janks. Meanwhile, Roxanne is interested in some financial advice and Lily, in an effort to bring them closer, suggests working with Neal, but things become increasingly awkward after a sexual mishap during their first meeting.
Whitney and Alex scheme a way to skip out on their family gatherings to start new holiday traditions with their friends Lily, Neal, Mark and Roxanne. However, Whitney's little white lie to her mother Candi and an unexpected visit from her father, Vince, cause her perfect plan of merriment to unravel.
In an effort to help Whitney earn some money, Roxanne hires her to be her assistant and office spy. Willing to do anything to help Roxanne, Whitney befriends Lindsay, the assistant to Roxanne's nemesis, and goes out of her way to appeal to her. Meanwhile, alone at home Alex takes it upon himself to do a little reorganizing. Elsewhere, Mark, who is dealing with a girl problem, enlists the help of Neal and Lily.
Trying out a new shapelier bra Whitney gets more than she bargains for when she entices Alex with her enhanced look. After Roxanne calls it quits with Lance, she asks Mark to help pack up his stuff, but things become complicated when Mark decides to take advantage of the situation. Meanwhile, Lily and Neal begin discussing a pre-nup, but the conversation leaves them wondering if they should even get married.