Gary wants to leave his girlfriend, Dorothy, but she decides to leave him first. Gary owns a flat and needs a lodger to help pay the mortgage. Unfortunately, he's got Dermot as a lodger and he's no help at all. A young woman named Deborah moves into the flat upstairs and Dermot immediately decides he's in love with her. The feeling isn't mutual though!
Dorothy demands an explanation when Tony sells one of her LP records, which is a 'rare' collectors' item worth £200, which is green in colour. Gary has to find a replacement! - The replacement LP is black, so Gary tries to paint it green! When Dorothy is not convinced, he has to pay her £200. Then, Tony tells him that there was a misprint in the catalogue - the green LP was only worth a few pounds!!!
Tony resorts to bugging Deborah's flat in an attempt to find out what she sees in her new estate agent boyfriend. Gary takes Dorothy to the ""Pasta Pig"" for a romantic meal. Carried away by the wine and the atmosphere, he forgets himself and proposes! - Dorothy accepts!! Next morning, Gary has second thoughts but how can he escape marriage?
Deborah leaves her keys with Tony so that he can let the gas engineer in to service her boiler. Tony can't resist the chance to have a peep in Deborah's underwear drawer, with disastrous consequences! Gary and Dorothy think they might have a baby - Dorothy begins to wonder whether Gary is mature enough to be a father.
Tony is away travelling around Europe. Meanwhile, Gary and Dorothy have a very romantic time and Dorothy decides that she'll move in with Gary. She also decides that Tony will have to leave the flat if he moves in! Tony comes home with a beard and is shocked to find a tidy flat with a fridge full of food instead of lager. Gary agonises about ways of breaking the news to Tony that he'll have to leave the flat.
Deborah has become interested in astrology. Tony thinks he can use this new interest as a way of getting her to sleep with him. Dorothy gives Gary a lesson in bad behaviour. Gary and Tony are horrified when they discover that Les has been sacked as manager of ""The Crown"". They're even more horrified when they learn that the new landlord plans to completely refurbish the pub. They set about finding a new 'local'. They also fill their flat with some strange mementoes of the 'old Crown'.
Gary makes himself look like a coward in a 'road rage' incident so he hatches a plan to make himself look macho. He hires someone to pretend to pick a fight with him in the pub but ends up fighting the wrong man. Deborah has a female friend staying with her. Gary and Tony are convinced that she's going through a ""lesbian phase""!
Everyone keeps telling Tony that he's getting fat, so he tries to lose weight. Tony discovers that Gary has £33,000 in his savings account and soon everyone knows about it. Dorothy 'persuades' Gary to make a donation to the hospital appeal fund but everyone is after Gary for a handout. He solves the problem by pretending that he's blown all of his money on expensive watches and Harrods lager.
Dorothy and Deborah have gone away on a sailing weekend. Tony is building a sauna in the garden shed - a ""shedna"" as he calls it. Gary and Tony meet Paula and Carol, who are staying at the house next door for the weekend. They invite the girls round for a barbecue. Tony makes a play for Paula, but discovers that she's a happily married mother. Gary is seduced by Carol. When Deborah and Dorothy come home, Tony talks Debs into trying out the ""shedna"" with him, but it blows up before they can use it! Gary obviously keeps quiet about his weekend activities with Carol.
A specially filmed scene in aid of Comic Relief brings a surprise guest to the flat.
In the final episode, Tony takes up his new job as a postman; however Deborah believes he's become boring as a result. Meanwhile Gary gets heavily drunk to break the news to George and Anthea the office is closing down; and Dorothy goes into labour, but with a drunken Gary and Tony (who’s now back to his old ways) and an unconscious midwife, events descend into disaster.
As part of Comic Relief 1999, a 'Swinging Sixties' version of the show was broadcast via recently discovered black-and-white footage, known as 'The Naughty Boys'.