The Vagina Captain's Logs
In regards to the OP, I don't think it would have been just his needs that she'd be giving in to. His needs would be part of it, but I think he was very interested in taking care of her needs and I don't see that changing in bed.
We all know who wore the pants in that relationship, especially on the planet. Chakotay would have made a good little wife. Unlike the other posters in this thread, I can't say if he would have been good or not, but he certainly would have tried.
Oh, and as for my vote, on that little canoe trip. I think they would have kissed on that trip, and that the barrier would have broken down.
Edit Speaking of a lack of barriers...you know she was still of child-bearing age at that point, right? Can you imagine her pregnant on the planet, or in natural child birth?