"I was a jerk and I was careless and reckless with the hearts of women I was with," the 39-year-old told Canadian show CLICK ON PHOTOS TO ENLARGE Michael Buble and Emily Blunt dated from 2005 until 2008 Michael, 39, and British star Emily dated for three years before their split in 2008 amid reports he had been unfaithful.

Emily, who inspired Michael’s 2007 hit song star John Krasinski and a mum to their daughter Hazel.

If you're reading this, it's probably somewhere near Christmas ... That's when self-proclaimed "Christmas prostitute" Michael Bublé always seems to resurface. On the bright side, she did inspire a heart-wrenchingly beautiful Buble song: "Lost." 2.

"Without it, I wouldn't have had a chance to fall in love with myself enough to be with a woman like my wife." Blunt herself recently addressed the cheating rumors, when she appeared on Howard Stern's Sirius XM show last month.

"I don't know, it's complicated," Blunt said, exclaiming: "I'm going red!

Buble married actress Luisana Lopilato in 2011, and the couple also has one child together, one-year-old Noah. "I learned about myself, I got closer to being spiritual and learned to be in the moment and realize how short life is.

It changed everything." He’s also learned a valuable lesson from his past heartbreak. I'm better at what I do, I'm better on stage because I'm not pretending to be the guy I want to be." VIDEO: Michael Buble on Reese Witherspoon arrest -- 'Everyone Makes Mistakes' ET caught up with Buble in August 2010, when he also got candid about his excitement at becoming a dad before baby Noah was born.