judgment

Assalamu alaykum,Will non – Muslims on the Day of the Judgment be punished according to Muslim laws or their laws. I mean f.ex males and females kissing each other on the cheek is haram in Islam, but for the Christians not. So will Christian who kissed each other on the cheek be punished for Allah for this because it´s haram or not because it´s not haram in their law?