Priscilla Chan and Mark Zuckerberg attended the UFC 300 event on April 13, 2024.Cooper Neill/Zuffa LLC via Getty ImagesJeff Bezos and Lauren Sánchez aren't the only couple that's stepping it up in the fashion arena.Mark Zuckerberg and Priscilla Chan were seen trying out the "mob chic" look at Saturday's UFC event. Zuckerberg rocked a fit straight out of Eminem's rapper-swag playbook, while Chan went for an all-black number.Step aside Jeff Bezos…