Robert Pattinson & Kristen Stewart back together, Caitlin Cronenberg 'cheating rumors' spark relationship drama? 'Twilight' heartthrob smoking again, stress prompts bad habit?

Rumors initionally suggested that things were going pretty well between former "Twilight" sweethearts Robert Pattinson and Kristen Stewart. The two aren't officially "back together," but there's a good chance that the infamous Robsten romance will blossom once again. Well, maybe...

UPDATE: Kristen Stewart 'replaced' with Robert Pattinson's love for animals, hilarious 'frolicking with cows' memes go viral on 'Life' movie set [PHOTOS] 

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Earlier this week, the British heartthrob was spotted flirting with alleged former flame, Caitlin Cronenberg. As Mstars previously reported:

Kristen Stewart ignores Robert Pattinson & Caitlin Cronenberg 'cheating' RUMORS: 'Twilight' starlet films new Sage +The Saints music video while R-Patz enjoys 'Life' movie set [PHOTOS]

Robert Pattinson 'dumps' Kristen Stewart for Caitlin Cronenberg romance, 'Twilight' heartthrob flirts with married former fling?

Robert Pattinson 'cheats' on Kristen Stewart with 'former fling' Caitlin Cronenberg? Twitter fans still support 'Robsten' love, rumors FALSE! 

Sources insist that the two are just "really good friends," but is R-Patz starting to feel the pressure from such ongoing gossip?

Over the summer, reports confirmed that the "Cosmopolis" heartthrob had "quit smoking" for good. At one point, puffing on cigarettes was something that Robsten actually "bonded" over. But after K-Stew cheated on Pattinson with "SWATH" movie director Rupert Sanders, the 27-year-old actor was allegedly ready to change his life around by making healthier life decisions. Well, not anymore.

Pattinson was recently spotted enjoying a cig on the Toronto movie set of "Life." Check out the photo here.

Maybe the stress from such a bustling Hollywood career and nonstop relationship "drama" is too much for Pattinson to handle?

Or who knows, maybe they were just filming a scene and the cigarette's actually fake.

Here's to hoping that R-Patz can kick the bad habit for good sometime soon! Maybe Pattinson and Stewart can work on quitting together?