Inside the Gibson Amphitheater at Sunday's Teen Choice Awards in Universal City, Calif., the country crooner, 21, and Twilight Saga star, 24, caught up in the audience and happily posed for pictures together.
(Swift wore a flirty Raphael Cennamo dress, a Ranjana Khan belt, Fendi shoes and Neil Lane jewelry; Greene sizzled in a tight Givenchy dress, Givenchy shoes and Neil Lane jewelery.)
No word yet on what they chatted about -- but they could have compared notes for hours on Joe Jonas. After getting together in summer 2010, the singer (who also romanced Demi Lovato and Camilla Belle), 21, split with Greene in March 2011 because he "wasn't that into it," according to one insider.
Jonas was way harsh with Swift -- dumping her in late 2008 via 27-second phone call. At the time, Jonas quickly rebounded with actress Belle. Swift got her, uh, revenge, with a song: "Better Than Revenge."