"There was no drama or ugliness. They just decided to end things," a source tells the magazine. "There is no hatred, just sadness."

Although they had been spotted around in Cannes, Austin, New York and Los Angeles -– neither had spoken publicly about the relationship.

Kate even attended Lance's three-day Livestrong Summit in Columbus, Ohio, this past weekend. That was where the decision to end it was made. To see photos of them at the Backstage Creations suite at the American Century Golf Championship on July 9, where they looked very happy and chummy.

Sheesh, they'd even met each other's families. Lance's mom liked having lunch with Kate at the Ivy by the Shore. And Kate's 4-year-old son, Ryder, went to a June Dad's Day brunch with Armstrong and his father, rocker Chris Robinson.

Armstrong's rep had no comment. A rep for Hudson could not be reached.

They seemed so perfect together. What went wrong?

Kate Hudson and Lance Armstrong Video