Real Housewives of Orange County star Vicki Gunvalson and her besieged boyfriend Brooks Ayers have become embroiled in a sleazy murder-for-hire plot, sensational court papers filed in Las Vegas charge.

Ayers -- the Bravolebrity's on-again, off-again lover -- has filed a slander and defamation lawsuit against Gunvalson's ex-business partner, who he claims went public with false allegations that he'd uncovered evidence detailing how Ayers planned to have him killed.