Honestly, I enjoy fluff just as much as the next person but this is starting to get absurd. You have two teenagers together on their honeymoon at a hot spring in an extremely romantic situation and completely naked...and they don't do it. Take any healthy teenage couple, put them in that situation and they'd do it. They didn't even properly look at each other's bodies. Smh.
With that said, I kinda get it. They skipped all sorts of steps by getting married like they did. They may be on their honeymoon, but they're still very much in the dating phase and are still getting to know each other. Still, I feel they know each other well enough and love each other enough to do it at this point. That and, again, they're on their honeymoon for crying out loud. Married couples do it daily (and usually several times daily too) on their honeymoons.
I agree with Kwijo. The special 4 pages aren't even needed. All that's needed is to see them in a futon together and kissing each other with their robes nearby to know they did it. That's it. That could take up one or two panels on one page.
The honeymoon isn't over yet though, so we'll see what happens.