Patriots quarterback Tom Brady was partying it up downtown Thursday night. Spies at Tenjune said Brady, most recently linked to supermodel Gisele Bundchen, was celebrating a buddy’s birthday there. We’re told Brady was checking his phone and avoiding a gaggle of blond models all night – “he explained to all the girls that it was ‘a guy’s night.’ ” Earlier, Brady was spotted with a blonde at Meatpacking hotspot Gin Lane, but sources there said she “was a friend . . . definitely somebody he knew.”