•
Phoebe Waller-Bridge as Louise "Lulu", a childhood friend of Anthony's, who moves into the hospital •
Jonathan Bailey as Sam, a sex-obsessed friend of Anthony's who grows closer to Fred •
Julie Dray as Melody, a French artist who becomes interested in Colin •
Louise Ford as Kate, a perfectionist engaged to Anthony who becomes at odds with Lulu •
Damien Molony as Anthony, a cook who is engaged to Kate and is a childhood friend of Lulu •
Adrian Scarborough as Colin Carter, a divorced colleague of Kate's who becomes a "muse" to Melody •
Amit Shah as Fred Patini, a gay man who becomes close friends with Sam •
Susan Wokoma as Jessica, Kate's bisexual co-worker, who has a sex addiction. Sam initially expresses an interest in sleeping with her, and she later kisses Kate. • Lockie Chapman as Will, Fred's self-absorbed Australian boyfriend. He works as a telephone volunteer at
Samaritans, and it is hinted that he is rich. •
Kathy Burke as Aunt Gladys, Lulu's eccentric great aunt who has an inappropriate sexual interest in Lulu. She is shown to be an alcoholic. •
Janie Dee as Cara, Colin's ex-wife == Episodes ==