Lindsay Lohan comes to Charlie for therapy and they begin a tumultuous relationship.

Charlie is held hostage by his prison group during a riot.

Charlie invites a new therapy patient named Bob (Bob Clendenin) into the group, who casually tells everyone that he is the devil. Nolan makes a deal with Bob to sell his soul in exchange for Lacey falling in love with him. When Lacey is all over Nolan at the next session, even the skeptical Charlie starts to wonder. Meanwhile, Jen falls for a new neighbor while Sam falls for a young man who appears to be the neighbor's son, but the two are later revealed to be gay.

Charlie goes too far when he gets jealous of Jennifer's much younger boyfriend, Canvas. Meanwhile, Patrick helps Lacey look sexy for her first modeling gig.

Charlie has to deal with the aftermath when his dad moves in with his patient Ed and they hit someone with their car. Also, Lacey takes Nolan out for a night of clubbing.

Charlie and Kate try to control their sexual urges as they begin work together on their sex study; Lacey starts a new job as a pharmaceutical rep.

Charlie inadvertently puts two patients together in a romantic relationship.

Charlie and Sean start a competition to see who can score first with a gorgeous woman.

Charlie spends the night with Lacey to keep her from killing her ex-boyfriend.

Charlie and Sean go to war when Charlie begins having casual sex with his ex, who is Sean's former girlfriend.

Charlie's trip with the group is interrupted when he gets some interesting news from Kate. Also, Charlie's house is unwittingly used for a porno shoot.

After Charlie and Kate have sex, he innocently asks her if she wants to go to a movie. Kate interprets this as a romantic gesture, rushes to fix him up on a date the next day with someone else and the two are forced to exam the nature of their odd relationship. At home, Sam kisses a girl at school and a picture of it ends up on Facebook.

Charlie suspects Jen's boyfriend, Sean, is cheating on her with his patient, Lacey. Also, Nolan's apartment gets robbed.

Charlie breaks all the professional rules by starting a friends-with-benefits relationship with a hot woman subject from the sex study. Also, Nolan and Patrick fight over a woman.

Charlie's Christmas plans with Sasha are derailed when Ed steals the baby Jesus from a Latino church.

Charlie asks for a second chance with the woman to whom he lost his virginity, and Lacey and Patrick try to keep up appearances when Lacey's parents pay a surprise visit.

Charlie tries to stop Kate from having sex with the executive in charge of funding their study; Charlie's dad tries to stop Lacey from throwing herself at a sleazy yoga instructor.

Charlie dates Jennifer's business partner and finds out she has sexual anger issues.

Charlie invites Ellie (Brea Grant), an attractive grad-student, to observe a therapy session only to have to compete with Nolan for her affection. Meanwhile, Ed and Martin come up with a plan to scam the government by hosting a disabled war veteran in their house.

Charlie is pursued by a hot reporter who wants to experience his sex study.

Charlie discovers scandalous information about Jen's new boyfriend, Sean, when he joins his therapy group.

When Charlie breaks it off with a police officer he's been dating, she abuses her power to make his life miserable. Meanwhile, Jordan struggles to establish a casual sex relationship with Sean.

Charlie seeks his prison group's help when his partying ways result in him getting arrested.

Charlie's neighborhood is up in arms when they find out he's been having clients with anger issues meeting at his home.

Inflamed by Kate's comment that he's only "nouveau smart", Charlie starts covertly dating a brilliant coffee-shop barista. The only problem is that the woman is turned on by sex where there's a chance of getting caught -- and she's Kate's patient.

Charlie goes ballistic when a drunk Jordan makes out with a prisoner.

Charlie and Jordan have to share a hotel room to expose a shady couple's therapist.

Charlie gets jealous and uses a patient to spy on Kate.

Charlie surprises his therapy group by bringing their dysfunctional parents to a session.

Charlie recruits Sean to help him throw the epic party of the century; Lacey inadvertently gets Ed hooked on drugs.

Charlie - a baseball player with anger issues turned anger management therapist - decides to return to therapy after a bad run-in with his ex-wife's new boyfriend. The only problem is he just happens to be sleeping with the one therapist he trusts: his best friend, Kate.

The new "evolved" Charlie has to deal with a ghost from his old carousing, baseball-playing days when a unattractive woman he slept with just to break a batting slump shows up as a new patient in group therapy.

Charlie has to make a decision between keeping his group and being a sports psychologist for a baseball team.

Charlie's dad falls in with a bad crowd.

Charlie and Jordan hire a hot tie-breaker to work as their associate on the prison clinic program.

Charlie begins a questionable romantic relationship with an ex-patient.

Charlie lets his house become a halfway house for five hookers.

When Charlie tricks Lacey into believing her father is broke, she gets engaged to an obnoxious billionaire. Meanwhile Nolan makes a business arrangement with Sean's strip club.

Charlie tries to keep Lacey from hooking up with a dangerous ex-con.

Charlie tries to help Patrick through a crisis of confidence by getting him stoned.

Charlie risks his life to sleep with a thrill-seeker.

Charlie interferes with Lacey and Nolan's love life and gets Nolan kidnapped by prisoners.

Jennifer moves in with Charlie temporarily and Kate gets jealous.

Charlie wants to make a business deal with Jordan's ex-husband, but he knows Jordan won't go along if she knows the identity of the business partner. Meanwhile, Lacey gets jealous when Nolan tries to save a family of birds.

Charlie wonders if his father is developing Alzheimer's.

Charlie lets his father help him coach a high school baseball team with bad results.

Charlie seeks his prison group's help when his partying ways result in him getting arrested.

Charlie gets in hot water with his prison group when he sleeps with the attractive new warden.

Charlie's plan backfires when he attempts to remedy his group with sleep-deprivation therapy.

A matchmaker sets up Charlie and Sean with the wrong dates.

Charlie begins seeing a new female therapist who used unorthodox therapy methods; Patrick tricks Ed into thinking he won the lottery.

Charlie's father sets him up with a hot, but quiet Catholic girl who turns out to be too wild, even for Charlie.

Charlie is in trouble when he finds out that a woman he had a one-night fling with is related to his supervisor.

Charlie uses Jordan to improve his online date rating.

Charlie's life is taken hostage by a controlling techy girl.

Martin has Charlie's daughter baptized behind Charlie's back.

Charlie is inspired to start a new clinic at the prison after Jordan wrecks their sex study.

Charlie becomes paranoid after discovering he's dating a private investigator.

Charlie goes to Vegas and life gets complicated after a night of heavy drinking.

Problems arise after Charlie has a threesome with his girlfriend and one of her friends, and Lacey uses Jordan's help to try and sell her eggs.