1. KRISTEN STEWART: Kristen and Robert Pattison always seemed a perfect couple. But unfortunately the couple broke up when Kristen cheated on Robert with her Snow White and the Huntsman director Rupert Sanders.
2. JENNIFER LOPEZ: She was married to Criss Judd when she met Ben Affleck on the sets of the movie Gigli and fell in love. She eventually cheated on Criss Judd and later divorced him.
3. MADONNA: Madonna was already married to Guy Ritchie when she met Alex Rodriguez. The two finally started dating. Even Alex was married at the time. Finally, they came clean about their relationship and divorced their respective spouses.