"Extra" caught up with supermodel Christie Brinkley at the "Heart of the Hamptons Celebrating the American Heart Association" event -- where she dished about her emotional state -- and what her cheating ex is up to.

"I'm very grateful for the public support. I really am," Brinkley said of the reaction to her highly publicized divorce proceedings against ex Peter Cook. "Throughout this whole thing, my children have been my primary concern." The New York Post claims Peter was spotted with new girlfriend Suzanne Shaw -- on the boat Christie bought for the family!

Brinkley ended her ten-year marriage to Cook in 2006, after a cheating scandal involving Cook and Diana Bianchi, an 18-year-old assistant.