Lauri Peterson's been a rock in Vicki Gunvalson's Louboutins all season, and on Monday's Real Housewives of Orange County reunion special, the fur flew as Vicki blasted her former friend for her rumor-mongering -- and accused her of cheating on her husband George, for good measure!

As we previously reported, in Lauri's return this year, she dished a series of embarrassing revelations about Vicki and her on-again, off-again beau Brooks Ayers, as revenge for Vicki circulating an inflammatory e-mail about George sent by his former mother-in-law.

On Monday, "The O.G. From the O.C." asked Lauri point-blank, "Are you miserable in your own life