Who knew that tight pants could inspire one of our new favorite late night dance-off battles?

Last night, Jennifer Lopez made a cameo appearance on the Tonight Show to challenge Jimmy Fallon to a “Tight Pants” battle, and it was pretty epic. The two of them shook their groove things in super skinny white jeans—but there could only be one victor!

J.Lo, looking super-fit and fabulous in a pair of J Brand 811 mid-rise skinny leg jeans, scared Fallon right out of town, playfully threatening the groovy late night host. “You better hide your wife! You better hide your kids! Because I will cut you!” she said. Watch the full video below, but fair warning: You may end up humming the song for the rest of the day.