Will and TJ go out on Valentine's Day, hoping to meet single women. Marcus turns to Chris.

Marcus feels betrayed after Will tries to impress Clay, his girlfriend Liz's son, Meanwhile Fiona is becoming a doula and trying to patch up Andy and Laurie's relationship.

Clay is trying to steal Shea away from Marcus, Meanwhile Liz feels there may be something strange about the relationship between Will and Fiona.

We follow perpetually-single Will as he attempts to woo women, while avoiding any real commitment. His life changes when a quirky, bohemian, vegan single mother, Fiona, and her 11-year-old son, Marcus, move in next door. Marcus is a misfit, and already being bullied at his new school, yet he and Will strike up an odd-couple friendship, under Fiona’s disapproving watch.

To Will and Fiona’s surprise, Shea accepts Marcus’ proposal to be his girlfriend. However, Shea’s idea of a boyfriend translates closer to a personal assistant than a companion. Elsewhere, Fiona attempts to be more spontaneous with Chris, while Will chaperones Marcus and Shea’s frozen yogurt date.

Will's new girlfriend Liz wants to hang out all day, the same day that Will volunteers to dig a hole for Fiona to throw all of her memories of Chris into to burn.

Andy and Laurie vacation apart, Fiona and Laurie have a Spa day staycation in San Francisco, while Will and Andy head to Las Vegas where Andy goes on a drunken spending spree on magic tricks until Laurie shows up to renew her vows with Andy. Meanwhile Marcus tries to read a romance novel to understand adult relationships to impress Shea.

Will agrees to babysit Marcus so Fiona can go on a job interview, but a last-minute invitation to a party complicates the situation.

Will struggles to pull off a guys' night out. Later, Andy asks Will to be his son's godfather.

Marcus asks Will for advice on how to get invited to a girl's birthday party.

Will returns to sort out a few things but ends up staying longer than planned when he sees Marcus's new "friends".

Music mogul Johnny Idalis listens to Will's new song, but wants him to improve the hook. Marcus is frustrated with his mother's burgeoning relationship and leaves to crash with Will.

Will is convinced that Chris is cheating on Fiona so he follows Chris to a hotel, where Chris reveals he has accepted a job offer out of the country, while Fiona prepares to tell Chris she loves him. Meanwhile, Marcus is trying to raise enough money to take Shea on a date to the movies so Marcus sells his silence to Andy for $100.

Will plays wing-man for Marcus, but Marcus wants to win Shea back at the school dance, Liz dumps Will after he defends Fiona, Marcus professes his love for Shea, Fiona and Will kiss.

Marcus develops a crush on a girl who has a penchant for trouble.

To celebrate a year of friendship, Marcus convinces Will to take him to the Golden Gate FemFest. Meanwhile, Dakota helps Fiona prepare for a night of intimacy with Chris.

Will accompanies Andy to the Bar Mitzvah of a music mogul's son.

Will is sued by an angry ex-girlfriend.

Feeling nervous about her first real date with Mr. Chris, Fiona wants Dakota to come with her as her safety net. Will ends up tagging along as well as he attempts to woo Dakota.

The Christmas celebrations are now in full swing but Will is not having a good time. With the lawsuit still pending, Laurie advises him to settle and move on with his life. Fiona and Andy attempt to create the perfect white Christmas for Marcus.

Fiona gets dating advice from Dakota.

Will invites Sam to a game night hosted by Andy and Laurie.

Scheduling problems arise as Will tries to plan a birthday party for Marcus. Meanwhile, Fiona and Sam get into a disagreement.

Will is told to sell his San Francisco home in order to solve his money issues. So he decides to find Marcus a brand new best friend.

Will invites Sam to move in with him after she is forced to evacuate her apartment. Later, Will and Marcus build a tree house.