This happened a few years ago. I was sailing for a week with some students from my university including my then girlfriend. We were sailing around the Stockholm archipelago, a stunning set of islands just off the coast of Sweden in the Baltic sea.
The smaller islands were generally uninhabited (perhaps they might have a holiday cabin or two and a sauna) and boats would spend the night tied up to trees on the shore, many of the island have great little natural harbours to do this in.
On one of islands me and my girlfriend went for a little walk, just the two of us. Started walking into the small forest on the island. After a while we sat down and started kissing. Pretty soon things started getting heavier, I began to run my hands under her clothes, slowly removing her top. At this point I started cursing that I hadn’t brought a condom with me, but ah well, we could still have some fun.