I dont think they actually had sex until they got to the bed, but I think that they probably started off there and Edward carried her to the cama o something.
Yes they had sex in the water and finished in the bed, tu can get to that conclution if tu read carefully pg 85 in Breaking Down when the pg is almost over where it says: "Forever," he agreed, and then pulled us gently into deeper water. And just then it's the siguiente día where they appear alredy in the bed.
I think she meant 6 times in total which includes them having sex when Bella was a vampire. I can't remember for sure if it was 6 times in total though.
actually they were seducting each other in the water.. and i think when they go under the water and they kiss, and mayb swin around each other, mayb even feel each other.
loll....
and then i think he carries her to the white cama inside, and carry on their HONEYMOON!!!
lectura the book, it is assumed that, but is not explicit. In the anterior night, Bella and Edward arrive at the house of the island and go swimming naked. Then, the only thing that we know is thar they wake up together in bed, nobody knows what happened in the water.