The 65-year-old, who had two affairs during their relationship, revealed in his memoirs that his romance with the Italian was a mistake.
"I haven't read any of the book, but I've been told," Dell'Olio told Hello! magazine. "I don't know why he's saying these things and being malicious.
"He clearly just can't let what we had go. My advice to him would be, 'get a life and get over it'."
The couple, who met in 1998, ended their relationship in 2007.