Real Housewives of Orange County Engagement Staged For Show?

Sources close to Gretchen tell TMZ, producers originally approached Gretchen's BF Slade about proposing -- hoping he'd pop the question in time for the show's big finale this year. We're told producers even attempted to bribe Slade with an exotic proposal destination ... and a FREE RING.

We're told Slade turned the offer down -- convinced the public already hated him enough without a fake proposal -- so producers turned to Tamra and her BF Eddie Judge out of spite.

We're told Tamra and Eddie instantly snatched up the proposal package -- and her whole proposal was then conveniently filmed for the show ... at the same exotic location that was allegedly offered to Slade.