In the third day of testimony in the cage match that is the Christie Brinkley-Peter Cook divorce, the supermodel told a packed courtroom she had to tell her kids "I think Daddy has fallen out of love with me."
Brinkley says just after learning her soon-to-be ex hubby was screwing around with an 18-year-old girl, she had to suck it up and throw a birthday party for 30 kids. She called that experience a "nightmare."
The cover girl also says she tried to avoid telling her children all about the dirty details of the break-up, including Cook's pricey porn habit.
Stay tuned ... they're in court all day.