Well, in a new interview with Details, Groban seems to suggest the rumors may have been true.
"We're very good friends. We met before her first album was even released, and we hit it off because we're both goofballs," Groban told the magazine.
However, when pressed further about it possibly being a bit more serious, the singer admitted: "We might have skated on the line of dating."
Groban also opened up about his relationship with January Jones. They began dating in 2003 before breaking up two and a half years later.
"We were madly in love. It was definitely my longest relationship," he said. "I'd love to get into another serious relationship. I am a real romantic at heart."