Jeff Bezos Sits Back, Watches Lauren Sanchez Bezos Party in St. Barths

Jeff Bezos is leaving all the partying to Lauren Sanchez Bezos ... because he took a load off while she partied her face off in the Caribbean.

The billionaire and his wife are down in St. Barths for the final days of 2025 and they hit up a day party Monday at Nikki Beach ... where Lauren was in full-on party mode.

Check out the pics ... Lauren is dancing and drinking wine, standing on a bench at their table in her denim mini-skirt and strapless top .... and Jeff's sitting next to her, just chilling and watching the party people do their thing.

Jeff and Lauren seem like they're always traveling, and he looks a little jet-lagged here ... but the same can't be said for Lauren -- she's like the Energizer Bunny.