Kristen Stewart and Robert Pattinson have been broken up for two years but it still hurts to see him with someone else, according to our source. K-Stew, 24, and R-Patz, 28, were the world’s Robsten but when Rob stepped out with Tahliah Debrett Barnett, 26, it seemed that chapter was over for good. R. Pattison holding hands with FKA Twigs in LA Kristen totally looked at the pics of Rob with the young, British singer, according to a source. For one, it’s the first time Rob has ever publicly stepped out with another woman, since their dramatic split in 2012. Secondly, they’ve been spotted together multiple times over the past two years and have even tried to get back together. “Kristen knows about Rob and Tahliah. It’s bittersweet,” an insider says. “I mean she’s happy that he’s happy, but it stings. She knows it must be serious if he’s being affectionate with her in public. She knows he’s ultra picky and wouldn’t hold hands with someone for the world to see...