The way underwear model and Baywatch actor Michael Bergin tells it, the last time he saw Carolyn Bessette Kennedy -- just one year before her 1999 death -- she begged him to take her back: ''I love you. I want to be with you.'' But Bergin refused: ''I love you... but if you think you're just going to get up and walk out on him, you're not thinking very clearly.'' Abs-obsessed Bergin tells a sordid, bottom-feeding tale about his life with Bessette. There's sex. Pregnancies. Drugs. The puppy that goes back to the pet store after 24 hours because Carolyn says, ''I can't even take care of myself.... How am I going to take care of a helpless little puppy?'' And on and on, all from a guy who has the credibility of, well, an underwear model. This book is a real air sandwich.