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"He's cheated on her for several years, and she just found out last week," a source close to the actress tells PEOPLE. "They never had a honeymoon, and he was out at a club last week without his wife."
No immediate word from Lopez's camp about the split or the reasons for it.
The couple, both 30, had been together for six years and tied the knot on April 24 in a Catholic ceremony in front of 50 guests at the exclusive Las Alamandas resort outside Puerto Vallarta, Mexico.
Landry, the former Doritos pitchwoman who currently costars on the UPN series Eve, first met Lopez while working at the 1998 Miss Teen USA pageant – she as a commentator and he as the pageant's host.