Charlie returns to his bachelor lifestyle after Alan moves out of the house. Alan suffers a breakdown after his divorce from Kandi.

Charlie finally tells Alan that he didn't marry Mia because she wanted Alan and Jake to move out of the house, but Alan finds a hole in his logic. Charlie and Alan deal with a noisy neighbor who constantly sings all the time, who happens to be Steven Tyler.

Charlie tries to surf to impress Dottie, a beautiful woman he just met, but after he nearly drowns he is convinced that he saw his late father.

Alan tries to hire his ex-wife's lawyer to help him win custody over the dog he and Kandi shared.

Alan is overjoyed by the prospect of Judith remarrying, as he would no longer have to pay alimony. Alan gets Charlie to help him when it looks like the marriage maybe derailed due to Jake’s dislike of his mother’s fiancé.

Charlie is dating a woman whose personality and life are like his mother’s.

Berta's daughter, Naomi is pregnant and Berta drags Charlie with her when she confronts the baby’s father. Alan reveals a secret fetish.

Alan suffers from insomnia. He visits his psychiatrist, who reveals that the cause of Alan's sleepless nights is his jealousy towards Charlie, and his inability to glide through life.

Charlie gets tired of Alan's mooching and reaches the breaking point during the brothers' double date. Jake is left home alone for the first time.

Worrying Charlie may get rid of one of them, Berta and Lydia fight over him. Meanwhile, Kandi does everything she can to stop Alan from selling their condo.

Charlie's friends and family put a crimp in his plan for a romantic Christmas Eve date. When Evelyn sees who the date is, she goes to great lengths to force a wedge between them.

Berta discovers that Alan has been dating her daughter Naomi.

Jake shares that he has heard his mother having sex with her fiancée, Herb; this revelation brings up a repressed memory for Charlie. This leads Charlie to seek help from Rose.

Charlie sets Alan up with their new neighbour. But he gets jealous when the two form a bond.

Rose is moving to London, and Charlie is surprised by his reaction to the news. Alan lies to a woman he met online.

Charlie's young, hot girlfriend takes him to a new club. She invites Alan to meet one of her friends but the men are shocked to learn that they are considered as being "old".

After Evelyn tells Alan and Charlie how she feels about there being no mourners at her friend’s funeral, the boys share their feelings that this could also be the case at her funeral. Evelyn tries to prove them wrong by introducing them to a couple she help adopt a boy from China. The boys return fire by inviting the young man to a play date with Jake.

Alan tries to bond with Jake when he realizes that his childhood is almost over. Kandi pursues a career in acting.

Charlie takes a liking to Myra, the witty sister of Judith's fiancé, Herb.

Alan looks forward to Judith's wedding, while Charlie and Myra continue their romance.

Alan and Charlie re-examine their sexual identities after Alan befriends Greg, a gay man. Meanwhile, Jake has a crush on Greg's daughter.

Jake gets lucky after Charlie takes him to the racetrack. Meanwhile, Alan has a difficult time at the DMV.

Charlie is shocked when the handyman working on his house beats him out for Chloe's affections. Alan has no sympathy for Charlie’s distress.

Evelyn's boyfriend, Teddy, invites Alan and Charlie to go with him to Las Vegas on his private jet. The boys confront their individual 'daddy issues'

Jake is getting ready to start a new school as he graduates to Junior High. Alan and Charlie take him school shopping and find themselves in trouble.

Charlie acts strange after spending an evening with his mother, and a woman Alan slept with behaves oddly the next morning.

Alan convinces Charlie that he needs to date more respectable women and sets him up with a judge. The two double date and their waitress happens to be one of Charlie’s ex-girlfriends. Charlie's date backfires the following morning, when he ends up in court in front of the judge.

Charlie and Linda get closer to consummating their relationship, but Charlie has trouble focusing when he begins to see Rose's face everywhere he turns.

Charlie has to come up with ways to keep his girlfriend's 4-year-old amused; Alan becomes a test subject.

Charlie's girlfriend is embrassed to go out in public with him. Meanwhile, Jake sneaks out to attend a concert.

After Alan and Charlie have a fight about Alan's role in the house. Alan packs Jake up and moves in with his mother.

Charlie writes a children’s song and finds success as Charlie Waffles. The children love him and the mothers seem to as well. Charlie's new found fame irritates Alan.

Charlie fights his attraction for Teddy's daughter.

Alan finds out that Charlie stole his girlfriend and works on a plan to get back at Charlie, even though this happened when they were in high school.

When Alan finds himself wanting to break up with a woman, Charlie offers his expertise.

Rose returns from England, and plays nurse rather oddly for an ill Charlie.

Alan finds out some surprising information about Judith's sex life when he decides to go on a date with one of her friends.

Charlie double-dates with Jake and fixes Alan up with a hooker.

Alan feels Charlie is unable to control his womanizing ways.

Alan makes wedding plans for Evelyn and Teddy, while Charlie figures out how to get more acquainted with his future step-sister.

CSIs investigate a death at Charlie's house.

Charlie's attracted to an older self-help author. Alan and Jake clash over a project for school.

When Charlie meets Angie's soon to be daughter-in-law, he realizes it's not for the first time.