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 and Kate are ready to sleep with the right people to get funding for their sex study Nolan's new online girlfriend turns out to be 10 years old.
A riot begins at prison and Charlie is held hostage by his group. Lacey, Nolan and Ed throw Patrick a surprise birthday party, but he has to hide the news of the riot from Sam.
Charlie gets jealous of Jennifer's much younger boyfriend Patrick helps Lacey look sexy for her first modeling gig.
Charlie mistakenly becomes a sex surrogate for one of Kate's patients Jennifer gets upset when Sam gets a tattoo.
Charlie has to deal with the aftermath when his dad moves in with his patient and they hit someone with their car Lacey takes Nolan out for a night of clubbing.
Charlie suspects Jen's boyfriend is cheating on her with his patient Ed and Patrick help Nolan after his apartment gets robbed.
Charlie begins dating a woman, not knowing that her brother is a serial killer from his prison support group.
Charlie learns a secret about Jen's new boyfriend when he joins his therapy group Ed moves in with Patrick.
Charlie steals a hot woman from an angry nerd. Lacey takes drugs in order to sell drugs.
Charlie begins seeing a new female therapist who has unorthodox therapy methods Patrick tricks Ed into thinking he won the lottery.
Charlie's trip to Lake Tahoe with the group is interrupted when he gets some interesting news from Kate.
After his breakup, Charlie starts a friends-with-benefits relationship with a hot woman subject from the sex study.
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 shakes up his relationship with Kate while dealing with the return of Jen's ex-boyfriend Charlie's group volunteers at a soup kitchen.
Jennifer moves in with Charlie temporarily and Kate gets jealous.
Charlie tries to persuade his father to join a choir of people his own age, a decision he later regrets. Lacey helps Patrick as an anger ally while he deals with a bully from high school.
Charlie begins a questionable romantic relationship with an ex-patient after the five-year mandatory waiting period runs out.
Charlie believes his father is faking alzheimers, and uses a hidden camera to spy on him. Patrick offers to help Nolan change his appearance to help his self esteem.
Charlie gets an invitation to his sister's baby shower and asks Kate to come along. Patrick decides to tell Ed that his daughter is gay.