Remember when former Dallas Cowboys QB Tony Romo and singer Jessica Simpson (Check out her Hot Shots Above) dated years ago?

Well, Simpson’s new book “Open Book” finally reveals why their 2-year relationship ended back in 2009.

RELATED: ESPN Reportedly Preparing to Offer Tony Romo a Record Deal

Who hasn’t been wondering what went wrong?

Now we can all rest knowing the reason.

Flip the Page to read the report: