Tennis star Melanie Oudin may have powered into the U.S. Open quarterfinals fair and square, but mom Leslie reportedly isn't afraid of playing dirty.
Oudin's mom Leslie is accused of cheating on husband John Oudin with Melanie's coach, Brian de Villiers, who led the 17-year-old Marietta. Ga., native to greatness at this year's Open.
John Oudin said in a sworn statement in early August that wife Leslie had been having an affair with de Villiers, the New York Daily News reported -- and that both Leslie and Oudin's coach confirmed they were having a sexual relationship.
"On December 29, 2007 I confronted my wife about whether she was having an affair with Brian de Villiers," SportsIllustrated.com reported John Oudin said in the statement.
"I confronted Brian de Villiers separately. My wife and Brian de Villiers both admitted to me they were having an affair," John said.
He also alleged that Melanie and her twin sister Katherine knew about the affair and that Melanie had knowledge of her mother and de Villiers sneaking away on tennis trips in the middle of the night.
"Both asked me point-blank if I thought Mom was having an affair with Brian," Oudin said in the statement.
Leslie Oudin said she wasn't unfaithful to her husband, but agreed as divorce proceedings continue to process to stay away from de Villiers apart from tennis-related activities.
John Oudin filed for divorce from Leslie in 2008, citing infidelity.