Mark worries he and Sophie are drifting apart and proposes. Elsewhere Super-Hans decides to give up drugs, and Jeremy once again gets intimate with past love Big Suze.

Jeremy's tortured relationship with his very sweet mother comes under the spotlight. It emerges that Jez has been living off handouts from his mum for years and now he's in line for half of her £40,000 bequest from an aunt. Jeremy's need to self destruct kicks in immediately, as does Mark's inability to stop his excruciating attempts to ingratiate himself with any mature grown-up. He adores Jeremy's mum and hero-worships her Scots Guardsman boyfriend.

Jeremy plans to throw a secret magic mushroom party in the flat, where he hopes to seduce his ex, Big Suze. But when Mark suddenly comes home from work with gastric flu, Jeremy's plans go to pieces.

Mark gets into online gaming and live role play with Dobby and wonders whether she may be The One. Meanwhile, Mark and Sophie finally sort out their annulment. Jeremy joins a cult.

Jeremy gets called for jury service but soon complicates things by falling for the defendant. Elsewhere, Mark & Sophie go clubbing.

Mark and Sophie return to work, while Jeremy renews his acquaintance with the depraved Super Hans, in yet another filthy, funny episode.

Mark and Jeremy are at the hospital awaiting the birth of Mark's baby. Sophie is determined to have a natural birth and doesn't want Mark to transfer any of his anxiety to the baby. Meanwhile, Jeremy is convinced he will never get over losing Elena, until he meets Zahra, whose boyfriend is in a coma.

Dobby, the object of Mark's desires, is now dating a graphic designer named Simon. Both Gerrard and Mark are determined to win her affections. Ben offers Jeremy the ideal job as head of development for his music web site.

Jeremy holds a book group at the flat in an effort to try and impress Zahra but apart from Mr Nice, Jeremy has never read a book. Mark is concerned by not being able to satisfy Dobby's sexual needs and decides to get some help for the problem.

It's Mark's wedding day. He is torn about whether he should go through with it or not. Jeremy discourages him but Mark continues. On the way to the reception, Sophie breaks down and runs away. Jeremy comforts Mark as the 'El Dude Brothers' are reunited.

Jeremy takes Mark on a stag weekend, with a rented canal boat. There, they meet two sisters, Aurora and Lucy, and their father. Jeremy falls in love with Aurora, whilst Lucy becomes sexually attracted to Mark. The father offers Mark a job in India, a way out of his impending marriage to Sophie, whilst Jeremy accidentally kills, and then eats a bit of Aurora's dog.

Mark and Sophie are finally beginning to go steady when Sophie is moved away from London for work. Mark is devastated, so Sophie offers phone sex as a solution, which Mark nervously accepts. Meanwhile, Jeremy is forced to consider getting an old friend sectioned.

It's not so long since Mark's new bride Sophie stumbled from the car, looking in appalled fascination at her husband of ten minutes and sobbed, "He's horrible!" As we return for the fifth series of this engagingly filthy comedy, Mark (David Mitchell) is getting drunk and maudlin on wedding champagne as his flatmate Jeremy (Robert Webb) urges him to go out on a double-date: "Beggars can't be choosers, she's an actual woman." Mark - remember, this is a man who once based his romantic strategy on the Siege of Stalingrad - arms himself with a copy of the Friends of the British Museum magazine and goes forth again to search for love.

Mark's baby's christening day arrives and he arranges to take Jeremy to the church with him. The duo end up getting locked in the hallway of Zahra's flat though.

Mark has invited his parents over for Christmas dinner. Everything has been planned down to the last detail but Jeremy has become over excited and Dobby and Super Hans show up as unexpected guests.

Mark has asked Dobby to move in with him, and Jeremy is faced with the prospect of moving out to make way. But Jeremy has been dragging his heels and Mark is increasingly worried that Dobby will move in with his rival, Gerrard instead.

Dobby is offered a job in New York by ex-boyfriend Simon. Uncertain about the offer, Dobby suggests that she and Mark spend a weekend in the country. The perfect time, as far as Jeremy is concerned, to get a few things off his chest.

Jeremy's love life takes a surprising turn, as Mark is dealing with his own matters of the heart.

Mark is depressed about Dobby on New Year's Eve but Jeremy is determined that the 'El Dude Brothers' are going to have the best night ever.

Simon, Dobby's ex-boyfriend, invites Mark, Dobby, Jeremy and Superhans to join him and his friends for a paintballing weekend. Mark is convinced that Simon is using the weekend as a cover to get back with Dobby, and Jeremy is convinced he can life coach Neil, Simon's best friend.

Mark continues to dread the impending doom of his wedding day, still questioning his actions from the previous season. Both Mark and Jeremy meet Sophie's parents and brother- leading to disaster with arson, sex with a parent and drunken arguments.

Jeremy finally runs out of money and finds himself on a downward spiral of hunger, homelessness and criminality. Meanwhile Mark needs to find a girlfriend before his birthday party.

Can you love two people at the same time? Jeremy believes you can, and his gorgeous new American girlfriend puts his taboo bashing beliefs to the test. Mark believes you can only love one person. Besides, he and Sophie, the object of his unrequited love, are getting on really well, especially since he starting hacking into her emails.

Mark, determined to forget Sophie, makes an effort to go out with April - but manages to blur the line between enthusiastic new boyfriend and stalker. Jeremy joins a new band, Executioners Bong, but insists that he is neither a roadie nor the equivalent of Bez.

Mark makes a final play for Dobby, the object of his desires. Meanwhile, Jeremy meets a new love, Russian émigré Elena. Both guys are determined to impress, but one of them is an expectant father. And when the pregnant Sophie spills the beans, both Mark and Jeremy's worlds change forever.