The carnival 'medium' Bella arranged for all girls at her sister Daphne Bloom's hen night convinces Bella she'll marry one of her exes within the year or die utterly lonely. Taking that seriously, she ignores her dependable ex Elliott Mayer, whom she only meets on account of shared custody of dog Rufus. Instead she tries to make up with hyper-emotive rock musician Johnny Diamont, whose heart she crushed a year ago by dumping him on his by-the-way-forgotten birthday. Johnny hesitates whether to take her back or exact just revenge.
Although finding ex Tommy's cat made belle volunteer to mind it, in the process she meets another ex, Jake Turner, whom she dumped after perfect months for 'stopping to make an effort' couch potato-style. He's now an editing executive and a physically stunning sports buff, so their dates prove bodily excruciating. Yet she ends up dumping Jake again on account of references to his other ex.
A burglar has robbed Bella. When she reports it, the police who arrives is Ronnie Helton, Bella's ex from 1991, her sophomore year. Bella's dad was not too fond of the "bad kid of the school", and does not like him 17 years later either. Bella, however, is very interested when she finds out that Ronnie is single.
When Cyrus convinces belle to come along and enjoy perfect surfing weather, they bump into her ex Shane Gallagher, whom she dumped for being an irresponsible beach bum, however hunky. Now he's a well-sponsored surfing star and still gorgeous, so she's interested again. Ironically, his obligations pose a problem, he now only plays the bad boy every woman swoons about. Augie finds the shower head he installed pleases his wife too much. Cyrus is after fringe benefits and a foxy girl who wants surfing lessons, but falls prey to Hawaian scam artist Mini Van.
Tommy finally comes to collect his cat, but to Bella's disappointment he brings along a wife and offspring. Hurting an eye proves a blessing in disguise, as Bella finds the ophtalmologist on duty is ex Dr. Josh Dupinski, whom she dumped for living with his devoted ma Arlene and lacking any macho spunk. He's now a great lover and adventurous surfer, and orphaned. Augie launches himself in designing logos, starting with a couple who want to use their portraits but can't agree how the old bat looks. Cyrus's elaborate dating scam backfires. Bella finds herself turning ...
During the rehearsal dinner for sister Daphne's 'Polynesian' beach wedding, Bella discovers groom Marty's sister is engaged to her own great teenage lover, known as Dude Ranch Steve after her best-ever summer holiday. Meanwhile Bella objects to her despised ma interacting at all with pa Bloom, who rebukes her. Bella pretends still to be with Elliot, only to learn later Steve broke off his engagement. They date nostalgically, but now all signs turn against them.
Bella is busy preparing a party for his father's 60th birthday, when she runs into Luke, an ex from 1999, who is now saving the planet. When Bella tells Cyrus that there are lots of female activists, he quickly goes to check them out.
Some of the gang have another go at Internet-dating, even pa Jimmy waves his worried daughters' objections concerning generation-mix, but Cyrus is the one who ends up dating his former kindergarten teacher. Bella thus reconnects with her adored arts professor Bertram Harris, an impressive hunk. he proves interested in dating her again and thus introduces her to his cool circles, but being his inspiring muse doesn't live up to her expectations at all.
Cyrus accidentally causes Bella to remember an ex from 1999, Steele Calvert. However, he cheated on her. And he has a secret. Also, Bella meets a new candidate, but isn't dating him against the rules of the Ex List?
Augie refuses to join Cyrus and Viv on hot Tony's Italian cooking course. Elliott has a new partner, vet Sara. Bella jealously tries to push away the utter lack of a physical spark when she meets again James, a now successful author, who isn't even bent on getting physical with her. Bella's parents to finalize their divorce, but memories get in the way. Elliot and Bella want to adopt the same dog and decide to give him Rufus's joint regime.
The next ex of Bella's is Wade, who proposed to her in 1996. Twelve years on, the proposal is off and he's divorced with a child, which is difficult for Bella. Augie is trying to muster the courage to propose to Vivian.
Cyrus follows Bella's example and goes to the fortune teller. Bella's next ex is Phillip from the 1990s. Turns out he is a successful architect. But Augie's new boss - who is not an "ex" - and Bella have instant chemistry. What to do?
At the bottom of on shrinking exes-list, chef Roy Avis, who has clear priorities, so Bella isn't allowed to play hard-to-get. Augie makes clear his professionalism now takes precedence over Viv's craving for daily bed-gymnastics. Several couples wrestle with the delicate question whether to diplomatically overlook each-other's sexual past or openly share it, at the risk of starting spiteful shenanigans. Cyrus got a dog as babe-magnet from Elliott and reveals the vet is about to propose to Sara, which kindles irresistible jealousy in Bella.