Jennifer Lopez stepped out to celebrate the 13 \"American Idol\" finalists, and all eyes were on the the sequin-clad stunner. The 42-year-old mother of two stole the show in a gold sequined minidress, showing off her signature gorgeous figure. The 42-year-old entertainer attended a party at “The Grove” earlier in the evening with host Ryan Seacrest and fellow judges Randy Jackson and Steven Tyler. After the show, the star went on a dinner date with her boyfriend Casper Smart.