The couple went for a stroll with their family members Sunday at a park near their Indian Creek Island property -- which is now Bezos' home base after leaving Seattle behind earlier this year. Looks like they're enjoying it out there ... 'cause they had some pep to their step.

Plus, they were dressed like it was June rather than December ... which we suppose comes with the territory in Florida -- it's pretty warm all year round, so they can get away with this.

Lauren was rocking a top that exposed her toned arms and shoulders ... whereas JB was showing off his legs in shorts. Of course, they were sporting shades too ... the whole fam was in fact. Talk about a power family -- that's the kind of vibe they give off as a unit.

Remember, Jeff and Lauren were just in the Caribbean last week enjoying a little holiday getaway together ... but it seems they wanted to be back stateside for Xmas Eve/Xmas.

It caps off a wild past few weeks for them, where they've been sailing the open seas and ringing in birthdays with friends in style ... with flash and cash to spare. Seeing them in a more low-key environment here seems to be them finally coming down off a year-long high.

They certainly look grounded and in lockstep unison ... telegraphing their marriage to come. It must be nice to be these two going into the new year -- they got a whole world to conquer.