Will returns to San Francisco to sort out his finances after a surprising royalty check. Andy reveals to him that his wife Laurie might be pregnant and he needs Will's help to find out. Meanwhile, Marcus's new "friends" don't sit well with Will and he attempts to convince Fiona that the kids are up to no good.
Will throws his annual Halloween bash; much to the dismay of Fiona and Marcus; who consider it one of their least favorite holidays. Despite the fact that Fiona believes Will has other motives for throwing the party; she ends up meeting Sean there and reveals a whole new side of herself. After a few mishaps at the party; Will shows Marcus the joys of Halloween.
Marcus (Benjamin Stockham) encounters the unimaginable while assisting the school principal for the day, when he meets Shea (guest star Izabela Vidovic), a 14-year-old rebel with a penchant for trouble. Quickly developing a crush, Marcus takes the fall for a school incident she was responsible for, leaving Fiona (Minnie Driver) and Will (David Walton) to face some major parenting conflicts in dealing with the situation.
Marcus (Benjamin Stockham) is ecstatic when a popular new teacher, Mr. Chris (guest star Chris Diamantopoulos) casts him as Romeo in the school production of notable Shakespeare scenes. Marcus asks Will (David Walton) to build the balcony set for his scene, however Will is more interested in watching "The Three Stooges" marathon with Marcus instead. Threatened by Mr. Chris' growing relationship with Marcus, Will tries to impress them with the construction of his balcony. Elsewhere, Mr. Chris not only has gained a fan in Marcus, but Fiona (Minnie Driver) as well.
With Christmas celebrations in full swing, Will (David Walton) is in agony over the cheerfulness around his least favorite holiday and the constant playing of his hit song "Runaway Sleigh." With his lawsuit still pending, Laurie (Annie Mumolo) advises Will to settle and move on. Refusing to give up any of his earnings, Will and Marcus (Benjamin Stockham) go on a search for the original handwritten song lyrics as evidence to prove he is the sole writer of the song. Meanwhile, Fiona (Minnie Driver) and Andy (Al Madrigal) try to create the perfect white Christmas for ...
Marcus and Will commemorate their friendship hitting the one-year mark in "About a Manniversary," and I believe the traditional one-year manniversary gift is an affectionate shoulder-punch. Meanwhile, Dakota helps Fiona ready for a night with Chris.
When Will (David Walton) learns Andy (Al Madrigal) scored an invite to music mogul Johnny Idalis' (guest star Greg Germann) son's Bar Mitzah, he sees an opportunity to get his music noticed and forces Andy to make him his plus one. With a push from Shea (guest star Izabela Vidovic), Marcus (Benjamin Stockham) convinces Fiona (Minnie Driver) to let him stay home alone while she is on a date with Chris (guest star Chris Diamantopoulos). During their night out alone, mischievous Shea takes Marcus party crashing while Andy and Will find themselves deep into a lie to ...
Just as Fiona is ready to deepen her relationship with Chris by telling him that she loves him, Will uncovers a secret about Chris that may change everything. At first he believes Chris is cheating on Fiona only to find out that he may be leaving town for a new job offer. Meanwhile, when Marcus discovers that having a girlfriend costs money, he ends up working for a very unlikely boss: Laurie.
Will is riding the emotional high of his budding romance with Liz the bartender. His high however runs in direct contrast to Fiona's emotional low after her breakup with Mr. Chris. Out of solidarity, Will pledges his complete emotional support to Fiona during what turns out to be a day-long mourning ritual. But when Liz invites Will to spend a few hours of free time with her on the same day, their first real date, Will is forced to juggle his commitment to both Fiona and Liz.
When a fight leads Andy and Laurie to separate vacations, Will struggles to handle an out of control Andy in Las Vegas while Fiona works to patch Laurie and Andy's marriage. Meanwhile, Marcus tries to get his hands on a novel that he believes is the key to his relationship with Shea.
Even with things heating up in his relationship with Liz, Will's not ready to start throwing around the word "girlfriend." Meanwhile, Fiona and Marcus are determined to patch things up between Andy and Laurie, whether they want their help or not.
Much to Will's dismay, Fiona and Liz begin to bond until she starts to notice how unconventional Will's relationship is with Fiona and Marcus. Elsewhere Marcus tries to take Shea out on a romantic date, but instead of falling deeper for Marcus, Shea begins to have feelings for Liz's son Clay.
Marcus is reeling after his breakup with Shea, and Will and Fiona have opposing theories and methods of how to help him get over his first great heartbreak. It all comes to a head at the dance where Marcus very publically tries to win Shea back. And Liz, frustrated with Will's attachment to Fiona and Marcus, finally breaks up with Will. Will blames Fiona for everything. And after a huge argument Will and Fiona end up kissing.