The guys go to Evelyn's house to meet the new man she's dating, and Charlie realizes the man's daughter is a woman he's trying to avoid.

Charlie nurses an ailing Alan back to health so they can go on a double date with two sisters, one of whom Charlie's been wanting to date for a long time.

Judith's devious siren sister stirs things up at Jake's 11th birthday party when she hits on Alan. Meanwhile, Evelyn brings alcohol and has a party of her own.

Charlie plays a tricky game when he gets involved with Alan's divorce lawyer, who could make things difficult for Alan if she were, say, dumped by a self-centered lothario.

When Jake repeats one of Charlie's sexist remarks in front of Judith's support group, the women convince Judith to stop Jake's visits with his dad and Charlie.

Judith is dating Jake's pediatrician, and Alan is upset until Charlie points out that if she remarries, his alimony payments will end.

The brothers throw out their mother, after she insults the way Alan is raising Jake. When Alan and Charlie ignore her phone calls, to get their attention she ends up in the hospital. When Alan and Charlie show up at the hospital they aren't sure if she's faking, and try to call her bluff.

Alan starts to worry about a medical procedure that he is facing, and to get his mind off it, Charlie suggests they go to Las Vegas.

When Judith decides to take a vacation, the brothers have to take care of Jake during the week. Alan finds it challenging, and even forgets to pick up Jake from soccer practice. When Alan finds out that he has to go to the I.R.S. because they're auditing him, he forces Charlie to take care of Jake, and Charlie doesn't do any better then Alan.

Evelyn buys Alan a new Sports car causing Charlie to claim that his brother has sold his soul to the Devil. The next day, Evelyn extracts payment by insisting that Alan go on a blind, double date with her, her new beau and his daughter. At the restaurant, Alan learns that his mother and boyfriend will not be able to join them because there was a mixup between his heart medication and Viagra and she didn't want to ""waste it"". As a result, Alan is left to deal with the daughter, who is on a weekend pass from a rehab center and still has some loose screws. Alan eventually gets her back to the beach house only to have her drive off in his new sports car and become the object of a televised high-speed car chase.

Evelyn demands Jake spend a night at her place when she finds out he spent Spring Break with Judith's parents. Neither Alan nor Charlie are keen on the idea, but going to a bar after dropping off Jake quickly erases their concerns.

Alan starts dating a woman with a Martha Stewart complex. Before long she's running the house with an obsession for perfection.

Charlie arranges a romantic date with Mia in the hopes of consummating their relationship. Alan begins to date Charlie's most recent ex-girlfriend.

Alan has trouble deciding if he should bring his younger girlfriend to Jake's birthday party to meet his mom and his ex-wife. Rose tries to get her boyfriend to act more like Charlie.

Alan tries to win Kandi back. Meanwhile, Charlie starts to sleep with her mom, Mandi, and Judith gets set up with her father, Andy.

Charlie and Mia start making their wedding arrangements. Things begin to fall apart when their two families meet each other. They eventually decide on a small ceremony in Las Vegas.

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.

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.

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.

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

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 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.

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

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 fights his attraction for Teddy's daughter.

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

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

In the 6th season opener, Charlie runs into an ex-girlfriend and a child who bears a striking resemblance to Charlie.

Charlie tries to help Jake's former teacher, who became a stripper after dating him, but things go from bad to worse when she has a religious conversion.

Alan tries to escape Judith's grasp as Charlie and Herb go on the prowl to pick up women. They later end up going back to Herb's hotel room with two prostitutes, where Herb declares his love for Judith and races over to win her back.

Charlie's new girlfriend Chelsea asks him to spend the night at her place, which puts Charlie well outside of his comfort zone, while Alan tries to enforce a punishment on Jake initiated by Judith for mooning a group of girls.

Evelyn offers to pay for Jake's college education, and Alan becomes listless because he has no compelling reason to work anymore, while Jake discovers a hidden talent in the culinary arts that may allow him to bypass college altogether.

Charlie finds himself re-examining his wild ways when an old friend dies and begins to feel that his time on Earth may be drawing to a close.

Judith is pregnant with a baby girl and Alan is convinced he is the father.

Melissa doesn't think Alan's family appreciates him, so she asks him to move in with her and her mom.

Charlie ends up in couples counseling.

Charlie has to remove a half-naked woman from his bedroom before Chelsea arrives.

Charlie's admission that he's in love with Chelsea gets a surprising reaction from her

Chelsea is asked by Alan to arrange a blind date between he and her new friend, unaware that her new friend is Rose.

Charlie mourns the loss of his bachelor pad as he reluctantly allows Chelsea to move in. Meanwhile, Alan discovers there is no longer much space left in the house for him.

Alan and Chelsea become best buds, and Charlie decides to take advantage of the situation.

Charlie must make a difficult decision about his future and with which woman he wants to spend his life: Chelsea or Mia.

Alan ends up playing maid to Judith's new baby as well as his former mother-in-law. Meanwhile, Jake uses an incriminating photo to blackmail Charlie.

Jake stops at nothing to get away from Charlie and Alan, after they embarrass him out in public.

Jake is taught the art of infidelity by Charlie, while Celeste is away for Christmas.

Charlie has a return engagement with Chelsea's best friend, while Alan has an unexpected effect on a new female patient.

Charlie is miffed over Alan's planned attendance of Chelsea's birthday party and suffers the indignity of having Jake chauffer him around following a license suspension.

Lyndsey and Eldridge move into Charlie's house after their home burns down.

Alan pretends to be Charlie when he goes out on the town; Charlie sneaks off for cosmetic surgery.

Charlie has difficulty dealing with dating a slightly older woman.