Thousands of hearts are breaking -- Joseph Gordon-Levitt has a secret girlfriend.

The Don Jon actor revealed the romance during an interview on SiriusXM's Howard Stern Show on Tuesday, Sept. 24.

"I have a girlfriend but I tend not to really like to talk about it in public," he told Stern during the sit-down. "She is not in show business."

The couple met through "mutual friends," he said, but the actor wouldn't go into further detail. When asked if he's in love, the Looper actor replied, "Oh, jeez, man! Come on! This is getting private."

The actor went on to explain why he doesn't talk about his personal life.

"I get up in movies and I play other people, so when the audience is watching me in movies, I don't want them thinking about me and who I'm dating, and blah blah blah," he said. "I want them to see the character, the story that I'm telling."

Earlier this week the young star appeared on Late Night with Jimmy Fallon, where he took part in a lip-synching contest with the host and fellow guest Stephen Merchant. Check out a video.