Violet panics when her wealthy sister Lillian plans a visit. Ash wants to introduce the group to his new girlfriend, Jess.

Feeling unfit, Freddie and Stuart join Ash at his gym, where a young fitness instructor persuades the pair to sign up for an expensive membership. With Freddie and Stuart spending so much time at the gym, Violet and Penelope discover how pleasant their flat can be without the bickering pair in it.

The gang decides to join Ash and Jess at a ballroom dancing class. Nimble on his feet, Stuart quickly becomes teacher's pet, leaving Freddie in a huff, while Violet becomes a hit with the amorous teacher in other ways.

After Freddie and Stuart have a falling out, Stuart moves in with Ash and Violet moves in with Freddie.

A celebration brings the whole group together but as always, it doesn't go to plan.