Andre Agassi said a pretty horrible thing to Brooke Shields in the middle of their nasty divorce back in the day ... so says Brooke, who decided it was finally time to call out her ex on live TV yesterday.
Shields was co-hosting the "Today" show and discussing divorce with legendary disso-queen Laura Wasser -- who was plugging her new book, "It Doesn't Have to Be That Way: How to Divorce Without Destroying Your Family or Bankrupting Yourself."
But when the topic turned to divorces that involve children, Shields chimed in with a shocker ... claiming Andre once told her, "Be happy we don't have children or I would not have made this easy for you."
After an uncomfortable laugh, she continued, "And therein lies why I'm not there anymore."
FYI -- Agassi and Shields divorced in 1999 after a rocky 2 years together. After they split, Agassi penned an autobiography in which he said he never should have married Brooke in the first place.