Robert Pattinson Movie Crush, Sienna Miller vs. 'High Life' Mia Goth: FKA Twigs Wedding Off?

Reports now confirm that 29-year-old British heartthrob Robert Pattinson will star alongside aspiring actress Mia Goth in Claire Denis' debut film, "High Life." But if R-Patz continues spending so much time on (and off) screen with a slew of stunning co-starlets (including Sienna Miller), will he eventually start ignoring fiancee FKA Twigs?

UPDATE: Robert Pattinson New Movie Crush: Beauties Patricia Arquette & Mia Goth Join 'High Life'

Pattinson enjoys working with 33-year-old Miller, and their chemistry (er, friendship) simply grew while filming the upcoming action flick, "The Lost City of Z" -

"They're spending a lot of time hanging out in each other's trailers and often meet up for late-night pub runs," an alleged insider tells Star magazine. "The cast and crew are picking up on the mutual attraction."

And where does that leave his relationship with Twigs?

"They fight. Rob threatens to break up with her and Twigs dares him to... With Sienna in the picture, no one would be surprised if he made good on his threat."

Such rumors were quickly denied, and the couple's engagement remains strong. But while Twigs remains focused on hopefully starting a family with her "Twilight" beau, Pattinson's movie career continues skyrocketing.

According to Deadline.com, Pattinson and Goth (a stunning model originally from London) were just cast in "High Life," which follows "a group of criminals who accept a mission in space to become the subjects of a human reproduction experiment. They find themselves in the most unimaginable situation after a storm of cosmic rays hit the ship."

Goth once dated Shia LaBeouf while working on Lars von Trier's controversial film, "Nymphomaniac." She will also star in Dane DeHaan's upcoming 2016 horror flick, "A Cure for Wellness."

Will Pattinson develop a little crush on the gorgeous young blonde, or will he finally tie the knot with his "Two Weeks" muse?