Jeff Bezos and Lauren Sanchez are kissing like there’s no tomorrow — playing lovestruck teens while cruising to their fairy tale wedding rehearsal in Venice … while all the world watches.

The PDA was full throttle — the couple were smooching and waving like royalty from their water taxi Thursday, with Jeff grinning ear to ear and Lauren beaming just as hard … looking surprisingly comfortable for someone dripping in extreme, skintight couture

Lauren was serving bombshell — rocking a sculpted off-the-shoulder midi with a metallic bodysuit that snatched her waist to perfection. If there was a pre-wedding health kick, it definitely did the job!

Jeff was giving full billionaire swagger — wearing a sleek suit, crisp wedding shirt, and looking every bit the mega-rich groom-to-be as they made their grand glide through Venice.

Of course, the A-list crew — including Orlando Bloom, Tom Brady and more — were also hopping on water taxis, ready to kick off the ultra-glam wedding weekend.