Robert Pattinson Betrayal HOAX: FKA Twigs Ignores Sienna Miller Flirting, 'Power & Beauty'

Robert Pattinson works very well alongside 33-year-old English beauty, Sienna Miller. Still, that does NOT mean that the former "Twilight" heartthrob is cheating on current fiancee FKA Twigs with his stunning "The Lost City of Z" co-star. Thankfully, 27-year-old Twigs continues ignoring such shady online rumors involving false allegations against her extremely loyal beau.

RELATED: Robert Pattinson Movie Trouble: 'The Lost City of Z' Violence Upsets Locals, Scares Animals

As MstarsNews previously reported, behind-the-scenes snitches insist that things are getting very hot-and-steamy between 29-year-old Pattinson and Miller while filming their new action flick - the sexual chemistry's undeniable!

"They're spending a lot of time hanging out in each other's trailers and often meet up for late-night pub runs. The cast and crew are picking up on the mutual attraction... Rob threatens to break up with her and Twigs dares him to [because they fight]. With Sienna in the picture, no one would be surprised if he made good on his threat" (via Star magazine).

But instead of lashing-out against such bogus and disheartening accusations surrounding their relationship, Twigs remains positive on Instagram in her own unique way:

@artshaman @matthew_josephs @wonderlandmag

A photo posted by FKA twigs (@fkatwigs) on Sep 16, 2015 at 11:13am PDT

And her music career continues soaring:

Had an incredible show last night at FYF! Thank you so much @dilarafindikoglu for my custom kimono. @giuseppezanottiworld for my archive crystal boots and @swarovski for helping me to sparkle all night! I love you LA you were incredible!!!! <3 photo by @gettiny.

A photo posted by FKA twigs (@fkatwigs) on Aug 24, 2015 at 10:06pm PDT

Meanwhile, Miller continues flaunting her own beauty online (without mentioning any movie "crush" on R-Patz):

#siennamiller

A photo posted by Sienna Miller (@siennamiller1) on Apr 6, 2015 at 11:21am PDT

#siennamiller

A photo posted by Sienna Miller (@siennamiller1) on Feb 19, 2015 at 9:04am PST

So, why do readers think so many webloids are out to "ruin" Pattinson's happy engagment - is Robsten still to blame?