Here's Bill's long-term girlfriend, Linda Holliday, stuntin' in a fishnet 1-piece somewhere a hell of a lot warmer than New England ... and lookin' damn good.

No sign of Bill -- guessing he's behind the camera in a hoodie.

It's the second beach pic Linda's shared since the Super Bowl ... but play time's over for her Coach Belichick, 'cause she also mentioned they just got back to Boston.

Sure Bill's stoked to get back to work -- though we bet he prefers hangin' with a half-naked Linda.

By the way, Bill and Linda reportedly met back in 2007 and began dating shortly after that. Since they've been together, the Patriots have been to 5 Super Bowls and won 2 of 'em.