A Bunch of Hornballs is the eighth episode of Season 4 and the 44th overall episode.
Summary
Jimmy goes out of town for a book convention; Gretchen decides to throw a divorce party for Lindsay, leading to an unsuspected visit from Paul; Edgar's friend encourages him to overspend on party planning.
Plot
Lindsay finally gets her divorce papers in the mail, and Gretchen suggests a divorce party.
Gretchen then asks Edgar to be the party planner, and Edgar accepts, though he is encouraged/swindled by workmate Max into throwing a lavish, expensive affair.
Lindsay is disappointed when her work friends refuse to show for the party, but a surprise guest—Paul—does show up after seeing photos of the party that Vernon posted. Paul taunts Lindsay, saying she is on her own and can no longer blame him for the bad things in her life.
After a conversation with Gretchen about childhood, Lindsay deduces that Becca is the cause of all her problems.
Gretchen, angered that Boone won't let her meet Olivia, tricks him into bringing his daughter to the party. Boone tells her he simply didn't want to get Olivia's hopes up regarding a new woman in his life, and the two decide they want to be an official couple and see where it goes.
Elsewhere, Jimmy attends an erotica expo to push his book. He later goes to an after-party and hooks up with a fellow author, though their coitus is interrupted when she has to throw up.
Jimmy gets a surprise call from Gretchen who, despite just committing to Boone, asks how he is doing at the expo and then wants to dish about Lindsay's party.