You're not truly a member of "The Real Housewives" family until you've been sued over a business deal gone wrong -- so congratulations, Dana Wilkey ... you're officially one of the gals now!
Wilkey, who joined the Beverly Hills gals in season 2, is being sued along with her fiancé, John Flynn, for allegedly defrauding an investor out of $53,000.
According to the lawsuit, filed this week in L.A. Superior Court, Mary Painter claims she invested money in 2008 with Wilkey, Flynn and another man ... who claimed she would get at least a 10% return on her investment. It's unclear from the lawsuit what exactly Painter was investing in.
Painter says she tried several times to pull her money out over the past two years ... but so far, she has not received a dime back.
She's suing for breach of contract and fraudulent misrepresentation, among other things, and is asking for her money back ... plus damages.
Flynn tells TMZ, "There is no fraud. Dana Wilkey is not a properly named defendant, and we expect to continue to negotiate and gain dismissal of this lawsuit as quick as possible."