Jake becomes Charlie's driver after Charlie has his license suspended, and to Charlie's chagrin, Alan makes plans to attend Chelsea's birthday party,.

Alan and Jake go on a road trip while Charlie is visited by the ghosts of girlfriends past.

Alan tries for an intimate night at a hotel with his new girlfriend, while Charlie takes a different approach to obtain the "girlfriend experience".

Jake's new friend, Eldridge, is a bad influence but Alan really likes his hot mom.

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

Charlie and Chelsea have a post-breakup one-night stand.

Charlie runs off to Vegas and returns with a new wife, but she's not Chelsea.

Charlie's jealousy threatens his relationship with Chelsea.

Alan ends up in jail after a bar fight, and Charlie worries that Chelsea might be interested in the lawyer who takes the case.

Charlie endures a colonoscopy to get out of a trip to see Chelsea's bigoted parents, only to return home and find them in his living room.

Jake writes love songs to woo his ex-girlfriend, and Herb and Alan hide their secret friendship from Judith's watchful eye.

Charlie coaches Jake on the art of infidelity while his girlfriend is away for Christmas.

Charlie discovers that Chelsea hasn't been completely honest about her finances.

Charlie is crushed when he discovers he hasn't been satisfying Chelsea and Alan attempts to cure his thinning hair on the cheap.

Chelsea invites her beautiful college roommate to stay at the house while she gets over a bad breakup.

Charlie and Alan wake up together in bed with a strange woman.

Alan recommends that Chelsea get breast reduction surgery and Charlie kicks him out.

Jake refuses to stay with Charlie and Alan after they embarrass him in public.

Alan takes a job working for Evelyn, and Charlie is forced to mend Chelsea and Jake's rocky relationship.

Alan plays nursemaid to Judith's baby and her tipsy mother. Meanwhile, Jake blackmails Charlie with an incriminating photo.

When Charlie's fiancée, Chelsea, convinces him to let Melissa, Alan's girlfriend, move in, the girls take over the house.

Charlie must decide between his fiancée, Chelsea, and his old flame, Mia.