Sam's chubby whale Rodney's fiancée Sherry has gone on the Zone diet and lost 46 pounds; now he's not sure he can marry her. In fact, all of Las Vegas is full of chubby people, in town for the Love ‘em Large convention at the Tropicana. Cooper's off to a bowling tournament and asks a reluctant Danny to buy a reining horse, Hay Maker's Mark at a Wyoming auction. Cooper can't make the purchase because the owner hates him, and the jet will be ready to leave in an hour.
Mike begs Danny to take him to Wyoming, claiming that he knows all about horses. Cooper charges Delinda with hiring a new chef for the restaurant. The food sucks since Wolfgang left. Delinda gasps, feeling the baby move for the first time. Cooper is the first one to feel the quickening. Danny can't feel the quickening, but he wants to be first, so Delinda tells him that Sam was first. Hot guitar guy William comes looking for Piper, and Sam sends him to wait for her at the bar.
Danny and Mike land in Wyoming where Cooper's truck is waiting for them. Danny teases city slicker Mike about his $200 jeans and fancy cowboy get-up. Sam isn't into keeping Sherry away from Rodney, per his request. She tells Piper that someone is waiting for her at Opus. Piper spies William singing a song about heartbreak at the piano, and disappears.
At the tables, Rodney flirts with chubby Keira, a lapsed Christian from the pick-up competition. Sam tells him that he needs to talk to Sherry or risk breaking her heart, and she'll only run interference for a little while longer. At the auction, everyone stares at Mike, as he discovers that he's allergic to horses. Danny's upset to learn that Hay Maker's Mark has been pulled from the auction.
Delinda's friend Ted is too busy to become the new chef, but he recommends sushi genius Meko. When Delinda refuses to eat raw fish because she's pregnant, Meko quits before he's hired. In the auction parking lot, Mike meets hot MILF Libby, who has allergies, too. When a horse whips Mike in the face with his tail, he passes out. Libby brings him around with an epi pen she had in her purse. She accepts his offer of a thank you beer, but huffs off when she sees his Cooper Ranch key ring.
Danny offers Hay Maker's Mark's owner, Dean White, a million dollars, but Dean claims his son Weston refuses to let him sell. After spying Rodney and Keira making out in a hallway, Sam finally locates Piper sobbing in one of the rooms, hiding from William. She keeps leaving him, but he always suckers her back in. Sam leaves Piper crying on Delinda's shoulder, and tells William who's performing for a crowd that Piper's sick.
Sam confronts Rodney, who admits he can't marry Sherry because she's no longer chubby. Sam squeezes Rodney's face, asking him to believe in the love and tell Sherry the truth. Sherry sees this, and accuses Rodney of cheating with Sam. Rodney tells Sherry the truth, but she refuses to gain weight. She smashes William's guitar over Rodney's head, throws her ring at him and takes off. Rodney fires Sam.
Weston's room is plastered with posters of hot chicks. He admits that he's not allowed to date until he's sixteen. Danny gives him his card, promising to introduce Weston to every hot chick in Vegas when he's 21 and seals the horse deal. He gets in the truck with Mike, who's still stewing about being abandoned by Libby. They see her drive by, and realize that she's Dean's wife. At home, Libby tells Dean that he just sold Hay Maker's Mark to Cooper.
Piper tells Delinda that she's just William's Vegas girl and she's tired of having her heart broken. Sam returns to the room to take a shift with Piper so Delinda can interview French chef Jean-Jacques. His food is great, and his resume says he went to Cordon Bleu, so Delinda says they must know lots of the same people. Jean-Jacques drops his accent, admitting that he's really from Tulsa - he just needed an angle to get past the competition. Delinda agrees to give him a trial run.
Dean and Libby chase down Danny and Mike, who evade capture by hiding in some trees. How are they going to get out of Wyoming with the horse? Delinda finds William picking up the pieces of his broken guitar. She tells him that Piper is crazy in love and has run off to get married with a fantastic guy. William doesn't care because he's already hooked up with Sherry. Delinda tells him to never return to the Montecito.
On her way back to Piper's room, Delinda spies Rodney and Keira running off together. She finds Sam and Piper drinking in bed as Polly acts out a romantic scene from "Notting Hill." The women agree that it's time to give up on expecting men to be perfect. Danny congratulates Cooper on winning the bowling trophy. Excited that Danny bought the horse, even if he paid too much, Cooper wants to know where he is. Wearing a face mask, Mike delivers a plate of carrots to Hay Maker's Mark, who is ensconced in Cooper's suite.