According to a recent interview with Details Magazine, Katy Perry and Josh Groban were SUPER close to being an item. Here's an excerpt:

DETAILS: Is it true you're friends with Katy Perry? Josh Groban: We're very good friends. We met before her first album was even released, and we hit it off because we're both goofballs.

DETAILS: Did you date her?

Josh Groban: No, not really.

DETAILS: "Not really"? It's simple, Josh: Did your tongue ever touch her tongue?

Josh Groban: [Laughs] I'm not commenting on that. We might have skated on the line of dating.

DETAILS: But you did date January Jones, before she was on "Mad Men."

Josh Groban: We dated for about two and a half years, and we were madly in love. It was definitely my longest relationship. I'd love to get into another serious relationship. I am a real romantic at heart.