A YouTube prankster has shocked his fans after passionately kissing his sister for a video posted to his channel, before speaking out to slam viewers who claimed the stunt was a hoax.

Chris Monroe, who is thought to be based in California, and is known online as PrankInvasion, stunned subscribers when he posted a video entitled 'Kissing my actual sister prank!' on March 22.

In the clip, the online star can be seen telling the camera that he knows he 'owes' his fans 'something big', before revealing that he was planning to kiss his sister, who is based in the San Francisco Bay area, in what has proved to be one of his most controversial stunts yet.

Shocking: YouTube prankster Chris Monroe stunned his subscribers when he filmed himself kissing his sister Kaitlyn O'Connor for a video that was posted to his channel on March 22

Controversial: Chris tells his fans that he knows he 'owes them something big' before revealing that he was planning to ask his sibling to make out with him

The video, which has racked up more than 5.3 million views in three weeks, has sent shock waves through his fan base, with viewers blasting the prank for a variety of reasons; some have slammed the stunt as fake, while others have criticized Chris for putting his sister in such an uncomfortable position for the sake of YouTube views.

'I owe you guys a crazy video, and in this one, I'm going to try and kiss my sister,' the sell-described prankster tells the camera at the start of the five-minute clip, before explaining that he was planning to ask his sister to play 'a really quick game for a quick kiss'.

He then clarifies that the woman in question - Kaitlyn O'Connor - is in fact his half-sister, meaning they are not 'fully' related, however he confesses that he knows that doesn't stop the prank from being 'really weird'. The fact that Kaitlyn is his half-sister also means that they are still blood relatives, however they share only one parent instead of two.

Chris also praised his extremely close relationship with Kaitlyn on his Instagram account just two days before the video was posted, sharing a picture of the two of them while writing: 'You’re my half-sister but it honestly doesn’t feel like it — so thankful we’ve stayed so close all our lives.'

After introducing the video, Chris proceeds to 'stalk' his sister for an hour, filming her from a distance as she walks around their house, before confronting her in her bedroom.

'I'm so nervous, I don't know if I should ask her,' he tells the camera. 'I've tried like five times to ask her because she's my sister and I don't want her to think I'm crazy.

'I feel like such a creep, I've been stalking my sister upstairs for the past hour. I feel like a creep so I'm just going to go up there.'

He explains that his plan is to go to her room under the pretense that he wants to film her for his candid 'vlog' channel, saying he will 'make conversation' with her before 'popping the question'.

Awkward: The YouTuber approaches his sister to ask if she wants to 'play a quick game for a kiss' and then challenges her to rock, paper, scissors, which she loses

Going in: Chris and Kaitlyn appear nervous before the kiss actually takes place, however they then make out passionately for several minutes

No stopping them: Despite pausing the kiss to check his phone when it rings, Chris then returns to the kiss, with the pair making out several times in the space of a few minutes

Once in her room, Chris videos himself chatting to Kaitlyn about old photographs that she has up on her wall - ironically focusing on pranks that she has pulled on him in the past.

'You guys think I'm the biggest prankster on YouTube? My sister should have her own channel. She's been pranking me since the beginning,' he tells his subscribers, while recalling a time when Kaitlyn smashed birthday cake in his face.

The video then cuts to the two of them sitting on Kaitlyn's bed, with Chris exclaiming: 'I finally got the courage to come up here and ask my sister if she wanted to play a quick game for a kiss.

'I'm literally sweating right now because I'm so nervous.'

After Kaitlyn says she's 'not really' keen to go ahead with the prank, she agrees, with her brother praising her for 'helping him out'.

The siblings then play a round of rock, paper, scissors; although they don't discuss the rules, it seems clear that if Chris wins, the pair will have to kiss, while if Kaitlyn wins, the prank won't happen.

Chris wins the round, rock to scissors, leaving his sister giggling nervously as he reaches for her face while saying, 'This is so awkward.'

'I don't even want to like hug you,' Kaitlyn tells her brother as the pair awkwardly try to get into a comfortable position for the kiss. As he leans in, she then pulls back, saying, 'No, stop. I don't want to kiss you.'

'Are you backing out?' he asks her, while she turns her attention to the bedroom door and says, 'I think dad might be here.'

Chris leaps up to make sure that they don't have any unwanted company before sitting back down on the bed and reaching his hands out towards his sister - who appears to feel much more uncomfortable about the situation.

'Close': Two days before the video was posted, Chris took to Instagram to praise his bond with his sister, saying that it 'honestly doesn't feel like' she is his half-sibling

Promotion: At the end of the video, Chris tells his viewers to go and check out his sister's Instagram account, noting that she is a 'model'

'One time, this is like a life experience, we won't forget this, it will like bond us,' Chris then tells his sister, before they quickly peck on the lips, and she descends into nervous laughter, wiping her mouth and saying: 'Ugh I'm going to go and kill myself.'

Despite her clear horror at the encounter however, the brief kiss does not have been enough for Chris's liking, and the YouTuber leans back in, pulling his sister's face towards his hand on the back of her neck.

The pair enjoy a much more passionate, open-mouthed kiss the second time around, with Chris holding his hands on his sister's face as she rests her arm on his shoulder.

Their embrace is interrupted by the sound of Chris's ringing phone however, and he breaks away to silence it, telling the camera, 'It's like the earth is trying to make it not happen, I'm getting a random caller in the middle of this, this never happens.'

Awkwardly, Kaitlyn seemed to think that she was, quite literally, saved by the bell, announcing that 'this is the end of this' - just as her brother turns back to grab her face once again, pulling her in for a third kiss, while telling her, 'Come here.'

Despite protesting 'no' as her brother grabs her head, Kaitlyn readily leans in for the embrace, wrapping an arm around her brother's neck as they proceed to make out for around 15 seconds, before Chris turns to the camera to stare into the lens, leaving his sister in a fit of nervous laughter once again.

Chris then turns back to his sibling and grabs her face for a fourth kiss, awkwardly tangling her hair up between their mouths, before they finally break away from their last embrace and turn to face the camera, Kaitlyn wiping her mouth in the process.

Too far: Chris spoke out over the weekend to defend the video against viewers who accused him of using an actress to pretend to be his sister

Over the top: Many viewers pointed out that Chris and Kaitlyn seemed too enthusiastic about the kiss, and questioned why they made out more than once

'How was that?' he asks, adding: 'I am literally sweating so badly. What was that like?'

His sister tells him: 'I never want to do that again,' as he falls back on the bed and says, 'What I do for YouTube...'

'Thank you so much to Kaitlyn for being in this video,' he says as he begins to wrap up the clip. 'Our relationship will never be the same again.'

He then reveals that his sister 'also models', and encourages his viewers to go and check out her Instagram - ironically noting that it's 'weird' that he's urging people to look at pictures of his sibling.

Unsurprisingly, the video racked up dozens of comments from shocked viewers, many of whom insisted that the video must be fake, joking that they couldn't wait for the video where he revealed the woman was actually someone he had hired for the clip.

However, Chris spoke to The Sun over the weekend, and insisted that they are most certainly related, proudly saying: 'She is my real half-sister. So, true she is not fully my blood but she is half and that is a fact.'

Other people accused the YouTuber and his sister of being too enthusiastic about the kiss, with one person writing: 'You said one kiss!!! You guys kissed like 10 times and enjoyed it!!!'

Another chimed in: 'Would it be wrong to say I feel like they do this all the time? They're just y'know a TINY bit too comfortable doing this?? You feel me??'

Some viewers joked that they themselves felt as though they had done something wrong by merely watching the video. 'I feel like I committed a crime just by watching this video,' one pointed out.