Real-Life Couple Justin Long and Kate Bosworth Play a Deadly Game in Trailer for House of Darkness

There's more than meets the eye for Justin Long in House of Darkness.

The actor, 44, stars alongside real-life girlfriend Kate Bosworth in the first trailer for Neil LaBute's upcoming thriller, which follows "a player out to score" (Long) who drives a woman (Bosworth) home after meeting at a bar.

While the man "thinks his beautiful, mysterious date will be another casual hook-up," the synopsis adds, "their flirtation turns playful, sexy and sinister. Hoping to get lucky, his luck may have just run out."

The 2-minute trailer begins with Bosworth, 39, and Long arriving at her dark "mansion in the woods," where things soon get cozy between them.

"You're not married, are you?" she asks him, before he replies, "Not at the moment" and she repeats back, slowly, "Not ... at ... the moment."

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Saban Films Justin Long and Kate Bosworth in House of Darkness (2022)

RELATED: Kate Bosworth and Justin Long's Relationship Timeline

Strange figures begin popping up throughout the house before Bosworth tells Long, "Let's play a game."

"You still don't understand what's going on, do you?" she later asks as he seems to descend further into paranoia.

"I'm tired. I'm gonna go home," Long says. "No you're not," Bosworth tells him in an eerily calm voice.

After Long asks near the end of the trailer, "Is that how it ends?", Bosworth responds, "Who said anything about ending?"

Saban Films Poster for House of Darkness (2022)

RELATED: Kate Bosworth and Boyfriend Justin Long Smile Together on Trip to Ireland

While their relationship is set to play out in a sinister fashion onscreen, Long and Bosworth have been all smiles in photos since confirming their relationship, after being seen kissing on a beach in Hawaii back in April.

The couple previously revealed that they filmed a project together in Arkansas — now known to be House of Darkness — after which Bosworth posted a glowing tribute to Long on Instagram with a carousel of photos, including one playful snap of him cradling Bosworth in his arms.

The Remember the Titans actress and the He's Just Not That Into You actor first sparked relationship rumors in March after they were spotted together in Los Angeles.

Since then, Bosworth has posted a sweet birthday tribute to her beau and the couple traveled to both Hawaii and Ireland together, with Bosworth sharing a photo from the latter trip to her Instagram in June.

House of Darkness, also starring Gia Crovatin and Lucy Walters, is in theaters Sept. 9, and on demand and digital Sept. 13.