Walden's attracted to a mom at the kids' gym.

Walden and Alan try to convince Louis that Santa's real.

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

Charlie is nominated for an advertising award but decides to boycott it because his arch nemesis always wins. Rose is having relationship problems with Gordon and seeks help from Charlie.

Alan starts to have financial problems when he starts paying for his girlfriend's bills, so Charlie tries to get him to break up with her. Meanwhile, Judith is after Alan because he's late in paying his alimony check.

Sheldon pushes himself to the limit when he collaborates on projects with Leonard and Howard as well as Amy on the same day. Meanwhile, Bernadette nears the end of her maternity leave.

Howard and Bernadette have a hard time leaving Halley in daycare when Bernadette returns to work. Meanwhile, Bert introduces the gang to his new girlfriend, Rebecca.

Leonard isn't thrilled when Penny considers taking a new job offered by her ex-boyfriend, Zack.

This is the one where it all began... Rachel leaves Barry at the altar, meets the gang, and moves in with Monica. Ross is reeling from his divorce from Carol who has become a lesbian.

Ross's lesbian ex-wife tells him at work that she is pregnant with his child and that her and Susan are planning to bring up the child. Rachel finds out that Barry and her maid of honour, Mindy, went on her honeymoon.

Everyone likes Monica's new boyfriend way more than she does. Phoebe discovers a human thumb floating in a can of soda & gets seven thousand dollars compensation, which she offers to Chandler to quit smoking.

Ross mourns the anniversary of losing his virginity to Carol. Rachel gets her first pay cheque but is angry most of her money went to FICA. The girls spy on the sexy politician across the street, George Stephanopoulos.

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

Charlie is nominated for an advertising award but decides to boycott it because his arch nemesis always wins. Rose is having relationship problems with Gordon and seeks help from Charlie.

Alan starts to have financial problems when he starts paying for his girlfriend's bills, so Charlie tries to get him to break up with her. Meanwhile, Judith is after Alan because he's late in paying his alimony check.

Sheldon pushes himself to the limit when he collaborates on projects with Leonard and Howard as well as Amy on the same day. Meanwhile, Bernadette nears the end of her maternity leave.

Howard and Bernadette have a hard time leaving Halley in daycare when Bernadette returns to work. Meanwhile, Bert introduces the gang to his new girlfriend, Rebecca.

Leonard isn't thrilled when Penny considers taking a new job offered by her ex-boyfriend, Zack.

This is the one where it all began... Rachel leaves Barry at the altar, meets the gang, and moves in with Monica. Ross is reeling from his divorce from Carol who has become a lesbian.

Ross's lesbian ex-wife tells him at work that she is pregnant with his child and that her and Susan are planning to bring up the child. Rachel finds out that Barry and her maid of honour, Mindy, went on her honeymoon.

Everyone likes Monica's new boyfriend way more than she does. Phoebe discovers a human thumb floating in a can of soda & gets seven thousand dollars compensation, which she offers to Chandler to quit smoking.

Ross mourns the anniversary of losing his virginity to Carol. Rachel gets her first pay cheque but is angry most of her money went to FICA. The girls spy on the sexy politician across the street, George Stephanopoulos.

Charlie is surprised to find out that Kandi has been living with them for the last three weeks.

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

Jake's teacher has a meeting with Alan and Judith to discuss the lack of interest Jake has at school. Alan starts to fall for Francine's intellect whilst Charlie helps Jake audition for his school musical.

After Leonard, Sheldon and Howard celebrate the completion of their top secret Air Force project, they're met with an unpleasant surprise.

On the tenth season finale, the gang is concerned when Sheldon's former admirer, Dr. Ramona Nowitzki resurfaces while Amy is away at Princeton.

Ross and Rachel wash their dirty laundry in public. Joey wants to go out with a woman who has a boyfriend, so he tricks Monica into a double date. Chandler recruits Phoebe to break up with Janice for him.

Joey gets cast as Al Pacino's "butt-double" but gets fired for overacting. Chandler starts a polyamorous relationship with an Italian woman but eventually learns that it's not all it's cracked up to be.

During a blackout, Rachel falls for the attractive Italian owner of a lost kitten just as Ross wants to profess his love. Chandler is trapped in an ATM vestibule with Jill Goodacre and desperately tries to impress her.

Ross and Monica go to the bedside of their dead grandmother, who momentarily returns to life. Chandler discovers all the gang thought he was gay when they first met him.

Herb asks Alan if he can go on a date with Lyndsey.

Walden risks losing Louis when his secret with Alan gets out.