Every second wedding’s gotta have a second honeymoon — seems like that should be a rule — and that’s why Ben Affleck and Jennifer Lopez are back in Europe for another romantic vacay.

Witnesses tell TMZ … Ben and Jen pulled up to the Grand Hotel Tremezzo in Lake Como, Italy Tuesday — arriving by private water limo, naturally.

The tables to the left of them were apparently kept empty … even a glass facade was moved so they could get a better view of the iconic lake.

Security was also nearby to make sure their night went uninterrupted.

And yes, we’re told they couldn’t keep their hands off each other — they put a pause on the kissing so Jen could head off to the bathroom, but when she came back they got right back to it!!!

Sounds like Ben was taking a look at Jen’s wedding pics on Vogue’s IG page — truly her #1 fan.

As you know, they said “I Do” for a second time at his Georgia estate over the weekend … after first eloping in Vegas last month. Wedding #1 ended with a family trip to Paris for their honeymoon.