As Marco (Allan Louis) and Keith (guest star David Monohan) prepare for their wedding with the help of wedding planner Olivia (guest star Griffin), Megan (JoAnna Garcia) discovers that her father Arthur (guest star John Allen Nelson) is drinking again. Megan and Lily (Kristina Apgar) lovingly tell their father how worried they are; unaware that he has received a letter from their mother asking him let her explain in person why she left. Sage (Ashley Newbrough) is upset when Rose (Lucy Kate Hale) reveals she plans to go on a wilderness trip over Spring Break, rather than going with Sage on their annual spa vacation. Zach (guest star David Franco) worries that Rose is changing and won't be interested in him much longer. Sage is shocked when Luis (guest star Ignacio Serricchio) tells her he doesn't believe in gay marriage and refuses to attend Marco's wedding. Megan gives Laurel (Anne Archer) the first draft of Laurel's biography and is relieved when Laurel loves it. Megan and Will (Brian Hallisay) have a fight where all of their pent up issues come out, and they decide to break up. Attending the wedding alone, Megan meets Simon (guest star Julian Morris, "ER"), a college friend of Keith's, and is unsure what to do when Will calls her the next morning to apologize.