The 21-year-old ex Disney star and the Canadian pop star reportedly spent the past few days together riding Bieber's three-wheeled motorcycle and attending mutual friend Alfredo Flores' birthday party.
"Justin and Selena are definitely full-on back together at the moment," a source told Us. "They spent all day riding together on a Can-Am Spyder on Sunset Blvd. Justin drove while Selena sat on the back holding on to [him]."
The insider added that Bieber "was incredibly sweet with her and they looked super happy and in love."
The couple was also spotted together in an Instagram video posted by rapper Khalil of Flores' birthday at a club's VIP room. Insiders claim the two "looked like a couple" and were "all over each other" during the celebration.
"It is always on-and-off," and insider said of the pair's relationship. "Same story, every other week, every year. Now they are together again, next week they won't be. They never stop talking, even when you don't see them together—that never changes. They fight, take a break, and then get back together. No surprise that it happened once again."
The couple's latest sighting comes days after Bieber shared and deleted a black-and-white photo of himself snuggling up to Gomez. The couple has been dating intermittently since 2010.