What did Lee Sang-soon do in the past that Lee Hyo-ri recalled him as “an insidious guy”?

Singer Lee Hyo-ri revealed how she fell in love with Lee Sang-soon.
https://kbizoom.com/what-did-lee-sang-soon-do-in-the-past-that-lee-hyo-ri-recalled-him-as-an-insidious-guy/