TV tonight: can ditching monogamy save these relationships?

7 hours ago 7

Open House: The Great Sex Experiment

10pm, Channel 4
The eye-popping reality show, in which couples attempt to open their relationships, returns for a third romp. Mark and Tanith wonder if having sex with other people can help build trust – especially after one of them cheated. Then there are childhood sweethearts Chloe and Paul, who have never had sex with anyone else … Hollie Richardson

Interior Design Masters with Alan Carr

8pm, BBC One
The game is on as the five remaining designers tackle their next brief: a hospitality suite in the home of English rugby, Allianz Stadium Twickenham. They have two days and £2,000 each to create something incredible, with one room being transformed into an ode to women in rugby. HR

Martin Clunes’ Islands of the Atlantic

9pm, ITV1
There’s more to Madeira than sweet wine, as Clunes discovers on his Atlantic voyage. The island is also home to high-speed rally racing and a forbidding statue of footballer Cristiano Ronaldo. Then it’s on to the nine-island archipelago of the Azores, where the cuisine is positively volcanic. Ellen E Jones

Black Snow

9pm, BBC Two

Julie (Kat Stewart) is under scrutiny and Leo’s (Dan Spielman) carefully constructed alibi begins to unravel like cheap tissue paper in the series finale. Meanwhile, a new lead about Samara’s (Megan Smart) mysterious caller forces Cormack (Travis Fimmel) into a race against time to protect her, a devastating confession from Will (Josh McConville) sheds light on Zoe’s (Jana McKinnon) fate, and another twist threatens to upend everything. Ali Catterall

Hacks

9pm, Sky Max
They might finally have got the late-night show off the ground – but at what cost? Without ever being too earnest, the razor-sharp comedy proves its heart as stressed millennial writer Ava (Hannah Einbinder) burns out. Will boomer boss Deborah (Jean Smart) really keep rubbing salt in the wound? HR

Austin

9.30pm, BBC One
When Julian (Ben Miller) faces having 100,000 copies of his children’s book pulped, he plans to break into the warehouse with Austin (Michael Theo) to rescue them from being turned into baby wipes – even if more than half of those pages just say “splat”. Elsewhere, Ingrid (Sally Phillips) has a meeting with a fancy ghostwriter. AC

Film choice

Still from The Living Dead at Manchester Morgue.

The Living Dead at Manchester Morgue (Jorge Grau, 1974), 10.10pm, Talking Pictures TV
This joyously tacky 1974 Spanish-Italian film is a rare instance of the continental zombie horror genre popping up in Britain. Filmed in the Peak District, though it’s pretending to be the Lakes, Jorge Grau’s chiller has corpses coming back to life thanks to a Ministry of Agriculture bug-killing ultrasonic radiation experiment. There’s a pleasing clash of cultures amid the shuffling undead attacks, as young folk Edna (Cristina Galbó) and George (Ray Lovelock) fight prejudice from Arthur Kennedy’s dismissive old Irish copper – as well as the flesh-eating hordes. Simon Wardell

Frank (Lenny Abrahamson, 2014), 2am, Film4
The irony of making the pleasing-on-the-eye Michael Fassbender wear a papier-mache head for most of the film is only one of the joys of this offbeat drama. Lenny Abrahamson’s comic tale of musical integrity is inspired by the life of Chris Sievey and his character Frank Sidebottom. Domhnall Gleeson’s pianist, Jon, joins the charismatic singer’s avant garde psych-prog group (to the disgust of Maggie Gyllenhaal’s synth player, Clara) and tries to nudge them towards popularity. But there’s a darkness behind Frank’s mask that lends the caper a more serious face. SW