Bill Belichick's Girlfriend All Smiles With Coach In Cute Social Media Post

Bill Belichick's clearly smitten with his girlfriend -- the legendary coach cracked a rare smile with Jordon Hudson in a recent social media post ... showing he's not just a grumpy guy after all!!

The 23-year-old cheerleader took to Instagram to recap her summer ... with multiple pics featuring the eight-time Super Bowl winner grinning from ear to ear alongside his boo.

In one of the snaps, you see the 72-year-old rocking a piece of Taylor Swift merch alongside Hudson ... with a beautiful sunset and lighthouse serving as the backdrop.

Another photo shows the two staring into each other's eyes while seemingly out on a hike.

As we first reported ... Belichick and Hudson became an item shortly after he exited his long-term relationship with Linda Holliday.

The two first met on a flight from Boston to Florida ... where they bonded over a philosophy project Hudson had been working on.

While they've been together for some time now, BB and JH have become more public with their relationship over the past few months.

They've also been living under the same roof -- as we reported, they moved in together around the start of the New Year.