Ali Fedotowsky and Roberto Martinez on March 30, 2011 in Century City, California. Credit: Michael Kovac/FilmMagic

They never made it down the aisle, but Ali Fedotowsky and Roberto Martinez did make a trip to the bedroom.

The exes reunited at fellow Bachelorette stars Ashley Hebert and J.P. Rosenbaum's wedding in Pasadena, Calif. on Dec. 1. Sources tell Us Weekly Fedotowsky, 28, hooked up with her ex after the ceremony!

One witness tells Us they were "inseparable." Indeed, Martinez, 29, moved tables to sit next to her.

"They started talking again a month ago," a pal says of the exes. Fedotowsky and Martinez split in November 2011 after an 18-month engagement; the duo connected on the sixth season of The Bachelorette in 2010.

But the hook up doesn't necessarily mean a reconciliation is in the future.

Says the source, "Chances of them getting back together are slim, but they had a great time."