Watch Kate Bosworth and Justin Long's Night Turn Deadly in 'House of Darkness' Trailer

Justin Long and Kate Bosworth House of Darkness
Saban Films/YouTube

The real-life couple's night turns deadly in their new flick.

Justin Long's date with Kate Bosworth doesn't quite go as planned in their new flick. The real-life couple stars in Neil LaBute's upcoming thriller, House of Darkness, and the first trailer teases how what was meant to be a casual hookup turns into something sinister.

Per the flick's synopsis, a player out to score (Long) thinks his beautiful, mysterious date (Bosworth) will be another casual hookup when he drives her home to her secluded estate after meeting at a local bar. 

While getting acquainted, however, their flirtation turns playful, sexy and sinister, hinting that, while Long's character was hoping to get lucky, his luck may have just run out.

In the trailer, just as Long and Bosworth start to get intimate, creepy figures begin appearing throughout the house. When Bosworth suggests that they "play a game," Long's refusal isn't exactly accepted. 

"You still don't understand what's going on, do you?" she asks him. While Long tries to escape, Bosworth refuses to let him go, and things only get worse from there.

"Is that how it ends?" Long asks Bosworth. "Who said anything about ending?" she eerily replies.

Long and Bosworth first sparked relationship rumors last year, after they worked together on House of Darkness

After shooting wrapped on the project in May, Bosworth took to Instagram to gush over her co-star, writing that he's "a truly spectacular / fun / funny / kind / rare / thoughtful / totally. fckn. rad human being."

Three months later, Bosworth officially announced that she and Michael Polish, her husband of nearly eight years, were calling it quits.

Then, in December, Long referred to his "girlfriend" during an episode of his podcast, Life Is Short With Justin Long, though he offered no other details about her identity or their relationship.

In April, Long spoke about his still-unnamed girlfriend on The Viall Files podcast. Long said that, before getting into a relationship, he'd "gotten to a place where I was comfortable with myself." While he "didn't know it at the time," Long said he was "ready for the one," whom he's now "found." 

"I want to [talk about it], but I also want to be protective," Long said of his relationship. "I want to scream it from the rooftops, but I also want to be protective. It's sacred."

That same month, Long and Bosworth were spotted kissing in Hawaii.

"They both went into this relationship without any expectations or pressure -- it was just fun and easy -- but things quickly got serious," a source told ET of the couple the next month.

During an appearance on the Dear Chelsea podcast shortly thereafter, Long gushed about his relationship, saying, "I’ve never had anything like this before."

Later in May, the couple went Instagram official with their romance. Bosworth took things up a notch when she celebrated her love's birthday on the social media platform the next month with a sweet poem.