"I think that's why our relationship is so special -- we truly started as friends," Longoria, 38, told the magazine.
Longoria met Arguello, 34, last year when he was cast in "Ready For Love," the short-lived reality dating show she produced, but they didn't begin their romance until recently.
"I guess we have the press to thank for pushing us to see something we didn't see!" the actress said.
"Eva and Ernesto are a perfect match," a source told People.com.
"They both speak Spanish, have the same religion and the same cultural background," the insider said. "Their friendship and their similar philanthropic interests laid the foundation for their new romance. ... They're very much in love."