Robert Pattinson and Kristen Stewart have been seen hanging out together in Los Angeles several times in the past week. On Thursday, they went with Pattinson’s friend Marcus Foster to Bobby Long’s concert at Hotel Cafe and went unnoticed by fans. “Robert was super low-key when he walked in,” an onlooker told people.com. When Long, who’s also a friend of Pattinson’s, finished his set, the trio quickly left the club and jumped into a cab. Then on Friday, Pattinson and Stewart returned to Hotel Cafe to watch Foster perform. “Kristen and Rob, just the two of them, came in and walked towards the curtained-off area on stage where they watched Marcus,” says a source. “They seemed to go unnoticed.” After the show, the two went with a group of friends to Chateau Marmont. The co-stars are rumored to have begun dating during filming of The Twilight Saga: New Moon, but have managed to keep their relationship under wraps for several months. A source said: “Word on the set of Twilight is that [Michael] Angarano, [Kristen’s boyfriend], and she are completely broken up. While people don’t want to talk about it, everyone is pretty convinced that Pattinson and Stewart are hooking up.” The two have since flown to Vancouver to begin filming Eclipse, the third movie in the series.