Robert Pattinson 'dumps' Kristen Stewart for Katy Perry? 'Twilight' heartthrob & 'Dark Horse' beauty spotted together at Coachella, hook-up rumors swirl behind (ex) girlfriend's back [PHOTOS]

Forget about those "Robsten romantic reunion" rumors - apparently Robert Pattinson still has a "thing" for Kristen Stewart's gal pal, Katy Perry!

Apparently, K-Stew wanted to celebrate her 24th birthday at Coachella this weekend (alongside her on-and-off again boyfriend, R-Patz).

But here's the thing - the 27-year-old British heartthrob was actually spotted at the popular music and arts festival with "Dark Horse" beauty, Katy Perry!

Rumors suggest that the two "secretly" hooked-up in the past. John Mayer's ex has always had a celebrity crush on the "Twilight" hottie, and she's allegedly taking such flirtation to the next level.

Pattinson and Perry were spotted watching Lorde and Pharrell performances at Coachella together on Saturday (April 12). And K-Stew was evidently nowhere in sight. The two "close friends" appeared to be having a great time. Check out Perry in her green-haired glory:

In one of the fan photos posted on Twitter, Pattinson can be seen standing behind Perry in the background.

Yeah, maybe they're just good friends enjoying a concert together. But still, with all the drama involving Perry and Robsten, maybe they should take a break...

Do Mstars fans think Stewart is at Coachella with her (ex) boyfriend, but they're just keeping things on the down-low?