MBLAQ's Lee Joon had an incident where he had to break up with his girlfriend because of a certain male celebrity. During the filming of "Strong Heart", Lee Joon revealed, "I had to break up with my girlfriend because of a male celebrity. ...My girlfriend was looking through my cell phone and saw the name of that male celebrity. She said that she thinks she knows that person, but we dismissed that thought by assuming it's just another person with the same name. However, we later found out that the person in my phone was the same person my girlfriend was thinking of." Because of that reason, Lee Joon had to break up with that girlfriend. What was even more shocking was when he later revealed, "That male celebrity is right here with us today." Be sure to check out the rest of Lee Joon's story (including the identity of the mysterious male celebrity!) on this week's episode of 'Strong Heart'. Source + Picture: DongA News via Yahoo! Korea