But viewers were left divided over the instalment, which saw Louis travel to Oregon in America, where he took part in a 'blind-folded sensual dinner.'
The presenter stripped down to engage in the party in which people evoke pleasure through food and gently stroking one another.
Although inappropriate touching wasn't allowed, Louis made it clear he'd been given the green light from his wife, before joining in on the fun.
Of course, the dinner did eventually lead to kissing and sensual pleasure, but Louis was just there to enjoy the food.
The unusual episode left viewers divided, with one claiming: "I don't think I've ever felt so uncomfortable watching something ever in my life."
That made for awkward viewing but classic @louistheroux as ever! #AlteredStates
- James Howes (@jhowes17) November 4, 2018
"GIVE THIS MAN A PAYRISE. NOW," another demanded.
"I'd be well disappointed at that party," a third added. "Thinking you're getting a buffet then all of a sudden you're in a blindfold with 3 different people stroking you and sausage roll has taken on a new meaning."
Out of all the Louis Theroux documentaries that Polyamory episode was one of the strangest and most awkward...I just don't get it. Each to their own though I suppose ♂️
- Tomás Clarke (@ClarkeTomas) November 4, 2018
A fourth simply said: "I am DYING at how uncomfortable Louis is."
Thanks to @louistheroux I'm now aware of the world's most awkward conversation because I've just watched it unfold. Sweet deal when your wife refuses to invite you in on your threeway.
- Susie Verrill (@susiejverrill) November 4, 2018
The documentary saw Louis meet several 'throuples' and people who have multiple partners, as he uncovered the impact these relationships can have on people who aren't fully into the polyamory lifestyle.
During the three-part series, Louis will explore two different states with different ways of living.
In the second part, titled Takes My Baby, Louis will look at the different outlooks and attitudes towards adoption, and third installment, Choosing Death, will probably the most emotional of the series. Louis looks at the topic of euthanasia, and it's reported that the episode will show a man ending his own life.
Louis Theroux Altered States continues on BBC Two next week at 9pm.
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