Although she was the most popular morning show host in television history, there’s one person who’s definitely not a big fan of Katie Couric: Matt Lauer‘s wife! Annette Roque holds a grudge against Katie because she’s convinced Katie knew about Matt’s cheating and never told her, say sources.

As The ENQUIRER previously reported, Matt had a secret affair with 26- year-old Jessica Thorman just weeks before his and Annette’s October 1998 wedding.

Jessica was married at the time – and later divorced as a result of her relationship with the “Today” show host.

Matt and Annette briefly separated in 2005 amid continuing rumors of infidelity, but the couple managed to patch things up. At the time, Matt’s publicist Lauren Kapp refused to comment on Matt’s personal life and didn’t acknowledge the split – but Matt later admitted in an interview that his grueling work schedule had damaged his marriage.

Annette filed for divorce on Sept. 13 of last year – while pregnant with the couple’s third child – but called it off a month later.

Because Katie and Matt worked so closely together, Annette thinks that Katie must have been privy to the darker details of his personal life.

“Because Matt and Annette are still struggling with their marriage, Annette can’t help but go over the problems they’ve had with a fine-tooth comb,” said the insider.

For the steamy scoop on Katie’s love life, pick up this week’s ENQUIRER — on newsstands now!