Olivia Culpo Rocks Tiny Bikini In Hot Tub During Vacation With Christian McCaffrey

Olivia Culpo made sure to pack plenty of bikinis for her Jackson Hole getaway with NFL superstar Christian McCaffrey ... throwing on a tiny two-piece for a dip in the hot tub -- and the pics are outrageous.

The model and Carolina Panthers running back have been heating up Wyoming this week ... and they've been documenting their romantic trip all over Instagram.

29-year-old OC proved she's able to withstand the freezing temps on Thursday ... by doing an impromptu photo shoot out in the cold while soaking in the jacuzzi.

The couple of nearly 3 years has been enjoying themselves in the Cowboy State ... playing billiards and backgammon, checking out the local fashion and posing for mushy pics together.

The lovely trip comes amid rumors C-Mac could be shipped out of Charlotte this off-season ... but he appears to be in great spirits throughout his R&R with Culpo.

No word on whether 25-year-old Christian was the guy behind the camera for the smokin' hot hot tub pics ... but if so, we salute.