Trevor and Carol organise a camping trip for the group of friends but are also rekindling the fire in their relationship. Sadly, the rest of the group are less enthusiastic. The boys get into trouble while on a bike ride.
John celebrates his birthday at a murder mystery evening with the couples all in fancy dress. However, a real-life mystery emerges - is it Maureen or her character, Lady Greystoke, who is having an affair?
Every year the gang goes away for a sixties weekend at Hollinger's Hotel, but this year is different, as Alan made an error booking the rooms, an old friend tempts Carol, and Trevor surprises everyone by attempting the climbing wall.
Mick returns from Spain without his young Russian wife Elena and soon causes chaos at the fete arranged by Carol. Meanwhile, John looks to spice up his and Maureen's relationship.
Only Alan is looking forward to seeing flashy Mick, widower of Jean, whose funeral everyone is attending, and who arrives from Spain with a 30-year-old wife and an air of being on top of the world, but all is not as it seems.
Joyce is retiring from her career, and Alan has taken the time to throw her a party. At home. John's tribute video is able to lift Joyce's spirits, however sudden news of their poor financial situation means she does not have to retire.
The gang are invited to a housewarming party for new neighbours Matt and Seb. Alan spots one of Joyce's old bedside tables in their house and thinks they have stolen it, so he hatches a plan to steal it back.
The couples attend the naming ceremony of Alan and Joyce's first granddaughter. John and Maureen are keen to get to know two well-connected party guests but they are more interested in Carol's erotic novel idea.
Maureen's mother, Joan, stuns everyone by announcing that she is going to marry a man 20 years her younger. The couples gather at the grand hotel for the ceremony and try to suss out Joan's groom, Roy.
Joyce organizes a 40th wedding anniversary party for Carol and Trevor, however, prior to setting out to the restaurant Carol confesses to Maureen and Joyce that she plans on leaving Trevor, potentially turning the celebration upside down.