The 28-year-old Australian actor, who met and got together with Hewitt when they played Noah Lawson and Hayley Smith respectively in Home and Away, said that he regrets ever asking her to marry him.
Brady told Woman's Day magazine: "I look back at it now and realise proposing to Bec was one of the biggest mistakes I ever made. It was just a stupid, young mistake and if I had my time over I would never ever have proposed."
He also revealed that he was heartbroken when Hewitt apparently developed a friendship with now-husband Lleyton Hewitt during their engagement.
He said: "I'm only speculating, but in the end I'm still not really sure why Bec broke it off - maybe it was because I didn't own a Ferrari!"