Gisele just gave us all a glimpse of Tom Brady that we've never seen before ... showing video of the greatest of all-time in nothing but his undies!!!
The supermodel just posted video of her hubby in a bathroom on her social media page, showin' off his fit bod and his latest Brady Brand boxer briefs.
Tom appears to be timid in the clip -- but Gisele was clearly loving putting him on camera, asking the Tampa Bay Buccaneers star about his skivvies over and over again in the quick vid.