Tony Romo ditched Jessica Simpson after striking up a close friendship with the daughter of his college sports coach, according to U.S. tabloid reports.
The pair shocked the showbiz world when they split this month (Jul09), coming so soon after rumours they planned to tie the knot.
However Us Weekly magazine alleges a second woman may have contributed to the break-up.
Sources tell the tabloid that in the months leading up to the split, Romo had been exchanging flirty text messages and emails with 22-year-old Natalie Smith, whose dad John coached the sportsman at Eastern Illinois University.
It's also alleged that Romo flew Smith to his Dallas, Texas home for a three-day stay shortly after he split from Simpson.
The insider tells Us, "They're not officially dating, but they are having an intimate relationship.
"No one who knows them is surprised."
When approached by Us, Smith denied she was anything more than "friends" with the Dallas Cowboys quarterback, insisting, "This is crazy. We have always been friends and there is nothing else to it."