"Real Housewives of O.C." star Gretchen Rossi's ongoing defamation suit against her ex-boyfriend just backfired royally, TMZ has learned, after a judge ruled she has to pay his lawyer fees.

Gretchen Rossi, one of “The Real Housewives ... must pay Photoglou the $40K, since the judge threw out the defamation part of her lawsuit against him, and Photoglou spent about $85,000 defending ...