I went to a small campground with a couple of friends.

The shower room had four heads, two on each end. When I went to shower, there were two guy on one end, both with semis, one younger, one older. I figured I interrupted something.

We chatted as we showered and it turned out they were father and son. This made me hard so I kind tried to hide it. Nothing happened then bit they told me where to find them.

That night I found them and we were drinking beer and they got cosier and we got more comfortable. We finally got to the point where they admitted they were sexually involved.

Turns out they had a fetish of wanting to be watched. So, we went in their tent and I got to watch the dad breed his son!!