Jack Osbourne takes Georgia Humphreys behind the scenes of Watching With The Osbournes: Portals To Hell.

Ozzy and Sharon Osbourne aren't the biggest believers in ghosts.

But their son, Jack, most definitely is. He presents a paranormal-investigative series called Portals To Hell, which sees him explore America's most haunted and sinister locations, in search of irrefutable evidence that a spirit world exists.

Now, a special watch party is set to air on Really, in which sceptics Ozzy and Sharon - self-isolating due to the coronavirus pandemic - catch up on a particularly terrifying episode of Portals To Hell.

As we follow Jack investigate the Shanghai Tunnels in Portland, Oregon, we get to witness his parent's reactions, while the TV personality also tunes in from his own home in LA.

At a time when he is having to socially distance from his parents, it "was a lot of fun" to make a programme together, says Jack, 34, who has dual American and British citizenship

"I can see them; I can go over to the house and stand outside while they talk to me with the door open, but it's just tough," he confides.

"That's something that's really been weighing on me and I've been trying not to think about it too much because it's just a really morbid thought of like, 'When will my kids be able to hug their grandparents again?'"

Londoner Sharon, 67 - best known for recent years for her role as an X Factor judge - and Brummie Black Sabbath frontman Ozzy, 71, first met in 1970.

They married in 1982 and went on to have three kids together, Aimee, 36 Kelly, 35, and Jack.

Between 2002 and 2005, the family (apart from Aimee) appeared together in the hugely successful MTV reality show, The Osbournes.

So, while they're used to being on TV together, did Ozzy and Sharon have any reservations about being filmed watching Portals To Hell from their sofa?

"I think they had reservations in the sense where they were like, 'We don't necessarily believe too much in this stuff, so I don't know if you really want us doing it'," admits Jack, who says the best job he ever had was ITV2 series Jack Osbourne: Adrenaline Junkie.

"They stepped up for sure. They're not the biggest ghost show watchers. They just don't like anything scary."

The star quips he was "slightly offended" to learn his parents had never watched Portals To Hell before.

For him, the paranormal is something he's been interested in since he was a kid: "I grew up watching X-Files - that was, like, my show."

But "the ghost hunting world is a tough world to crack into".

"Viewers at home and people that work in the field are very territorial and they're very sceptical about people," he continues.

However, a few years back he made two series of Haunted Highway, which followed he and his friend, actress Dana Workman, investigating claims of paranormal activity along America's remote roads. They travelled without a camera crew, shooting their creepy findings by themselves.

Then came Portals To Hell, which started last year (in America, it airs on the Travel Channel).

"When we were developing the show, I was never originally going to host it and then the network asked if I wanted to, and I was like 'okay, let's do it!' And it just happened really organically'."

The only downside to the show is the time he has to spend away from his kids (he has Pearl, eight, Andy-Rose, four, and two-year-old Minnie with ex-wife Lisa Stelly).

"It's so hard to do travel shows when you've got three kids at home, especially really young ones. It makes you yearn to be home more than normal. But, it's an awesome job."

Discussing shocking moments from shooting the second series, he recalls an episode about the Haunted Hill House in Mineral Wells, Texas.

"The amount of folklore surrounding this place... At one point they said that a satanic death cult lived there, and then they said there was a murder that happened there and then they said there's a demon that allegedly habits this place.

"So, I initially went into it being like, 'Yeah, sure; everyone's just a little bit too over the top about this place'. And that house was absolutely terrifying!

"Towards the end of the night, Katrina and I were upstairs, in basically a converted attic, and we heard the loudest bang on the wall - it literally sounded like someone took a baseball bat and just smacked the side of the house. Yeah, it was really terrifying."

Indeed, he finds it tough to switch off after the cameras stop rolling when they stay at the places they're filming at.

"I have the ability to turn it off when I go home and back to the hotel, most of the time. But the locations, I have a terrible time sleeping at.

"At Hill House, it was tough to put that out of your head, just because of how that investigation panned out. It was a really interesting case. We've never done anything like it."

The Osbournes are arguably one of the most famous families in the world.

In a candid interview with US show Good Morning America back in January, Ozzy revealed he has been diagnosed with Parkinson's disease.

Asked how his dad is coping with his health during lockdown, Jack says: "He's doing okay. He's just bored. He was going to go back in the studio and start work on another album, and that got all shut down, especially because his producer, he got Covid.

"He's had a really hard time with it. That hit very close to home - I think it really freaked my dad out at that point. But, he's doing good."

Watching With The Osbournes: Portals To Hell airs on Really, today, 9pm and is available on dplay