Walden begins to date a beautiful 22-year-old woman, but eventually finds himself more interested in her grandmother; Alan and Jake go on a bonding trip.
Alan is surprised when Charlie's adult daughter, who is very similar to her father, shows up at the beach house to connect with what is left of her family.
Four friends encounter difficult choices as they leave high school and prepare for the rest of their lives, each one trying to make a name for themselves.
Alan comes home with an ostentatiously distracting vase, causing Charlie to object to its presence in the house; Alan and Jake move in with a reluctant Evelyn.
Alan is thinking about breaking up with his girlfriend but he is unsure how to go about doing it, so Charlie lends him some advice on ending relationships.
After agreeing to accompany his nephew on a multi-generational double date, Charlie sets Alan up with a prostitute so he won't be left out of the romance.
Charlie must resist temptation when he meets the grown daughter of the older woman he has been dating and realizes that it isn't their first encounter.
Charlie terrifyingly contemplates fatherhood when he coincidentally runs into a former lover who has a son named "Chuck" that looks and acts just like him.
It's a series of firsts in the house as Charlie attempts cooking, Alan experiences dating two women at the same time and Jake takes his first taste of beer.
Alan is angered when Charlie begins hooking up with his receptionist, as he knows that their inevitable break-up will ultimately impact him more than Charlie.
Judith kicks Herb out of the house, providing Alan a golden opportunity; Charlie takes Herb under his wing by teaching him how to live the bachelor lifestyle.
Evelyn offers to pay for Jake's education, causing Alan to excitedly ponder retirement; Charlie becomes convinced that their mother is up to something.
When one of Charlie's oldest party-going buddies passes away while visiting him at his beach house, Charlie begins to reconsider his playboy lifestyle.
Charlie tells Chelsea that he loves her, but she doesn't respond the way he had hoped, causing him to go to great lengths in order to get her to reciprocate.
Jenny moves in with Evelyn and her boyfriend when Walden begins to feel cramped in his own house; Alan becomes the "other man" in Lyndsey's relationship.
Jack spots Chrissy with his money in her possession, and evidence begins to mount towards the conclusion that Chrissy has a strong compulsion to steal.
Jack becomes excited when Chrissy lands him a job catering an executive party at her office, but problems arise when he attempts to defend Chrissy's honor.
Mr. Roper discovers that he can hear into the trio's apartment through pipes in his home, and a misunderstanding leads him to believe that Chrissy is pregnant.