TV tonight: a formidable cast tackle secret families in The Other One

The Other One
9pm, BBC One

Following a heart attack at his surprise birthday party, Colin leaves behind a family in mourning and a love child and mistress in this new comedy series. Ellie White and Lauren Socha star as the long-lost half-sisters coming to terms with each other’s existence, while Rebecca Front tackles her newfound identity as the other woman. It’s somewhat heavy-handed when it comes to the gags on splitting up Colin’s ashes or his beloved boat but the formidable ensemble cast manages to hold this watchable sitcom together. Ammar Kalia

The Greek Islands With Bettany Hughes 
9pm, Channel 5

The historian sets sail on a Greek Odyssey that combines culture, myths and legends. If the beautiful blue seas and Greek salads aren’t enough to hook you in, the tale of Odysseus with its lust, drugs and battles might do the trick. Hughes starts her journey in Fourni, where she hits some choppy waters. Hannah Verdier

Reef Break
9pm, Alibi

Poppy Montgomery was the strait-laced FBI agent on Without A Trace, but now she has swapped her work suit for a wetsuit in this fun and silly beach-based thriller. Montgomery stars as Sherlock-with-a surfboard Cat Chambers, who returns to her island home, and immediately gets mixed up in a high-profile kidnapping. Ellen E Jones

Sex in Lockdown: Keep Shagging and Carry On
10pm, Channel 4

Anna Richardson returns with the answers to all our lockdown-related sexual queries in this resolutely post-watershed doc. Among the couples she profiles are a separated pair who have fashioned a replica penis to satisfy their needs, as well as a singleton breaking lockdown. AK

Jason Manford’s Muddle Class 
10.45pm, BBC One

The comic’s last standup show about “levelling up” to a middle-class existence (hummus, anyone? Skiing?) didn’t win any prizes for originality, but there are worse ways to spend an hour. And, with a smörgåsbord of class tropes and stereotypes on offer, you might just spot yourself. Hannah J Davies

Derry Girls 
11pm, Channel 4

The first season of Lisa McGee’s hilarious comedy on a group of schoolgirls’ lives during the Troubles in Northern Ireland screens tonight in its entirety. We open on the first day of the new school term as cousins Erin and Orla head into Our Lady Immaculate Girls School amid a bomb scare. It’s addictive viewing. AK

Film choice

Tormented (Jon Wright, 2009), 12.20am, BBC Two
In Jon Wright’s scary, witty and rude Brit version of a US high-school slasher movie, a bullied schoolboy kills himself, then returns from the dead to wreak vengeance on his tormentors, including Alex Pettyfer’s Bradley and Dimitri Leonidas’s Alexis; Stephen Prentice’s script has all the cruel humour of the playground. Paul Howlett