Less than three months after breaking off their engagement at the VERY last minute, Kristin Cavallari and Jay Cutler were seen holding hands in L.A. today.

Pretty shocking they would reconnect ... especially because Kristin had already taken pictures IN HER WEDDING GOWN when the two suddenly called it quits.

But the Chicago Bears quarterback was spotted in the audience at "Dancing with the Stars" last night ... and now, some P.D.A. in front of the photogs.