Chicago Bears quarterback Jay Cutler is planning on marrying Kristin Cavallari, but according to a Star magazine exclusive he may want to take another look at his future in-laws -- particularly his father-in-law, Dennis Cavallari.

The 25-year-old reality-TV star's father has been living a double life filled with greed, lies and adultery, and now his mistress of five years is coming forward to expose him.

"He told me he loved me and even lied about not being married in a desperate attempt to continue our relationship," Tracy Sill, from Orange County, Calif. told Star in an exclusive interview.