As I've noted elsewhere my best (male) friend and I are frequently nude together. In the spa, pool, etc.
Several years ago he was on a photo expedition with me, just as a companion while I was shooting landscapes in the desert. We weren't quite as comfortable then as we are now, but I figured he might be up for a few nude shots if the moment presented itself. (He's very athletic with a great body and nice dick and balls.) But after our first couple of stops all he did was take off his shirt. I figured, okay, maybe next time.
We stopped a few miles later and I was working with the camera shooting volcanic cinder cones which are in the desert east of Los Angeles. Stunning location almost nobody knows about. Along the opposite side of the road are some sand dunes.
While I'm shooting I realize my buddy has disappeared, so I start looking for him, walking up across one of the sand dunes to find him naked in the sun, fully erect and jacking in the dunes. He looks over and sees me, panics and starts to cover up. I - not stopping to consider my fortune - apologize quickly and go back over the dune, yelling for him to join me when he's done.
A minute or so later, still slightly tenting in his jeans, he joins me at the car and is obviously flustered, asking if I'd seen anything. I had, but it would have really embarrassed him. So I said "I've seen you naked before so no, nothing new." A couple of miles further down the road we stopped again, and I tried to get him to strip off but he refused.
Since that time, about a decade ago, we're far more open and he's posed for a few shots with me sporting a semi. (That's his cock I'm using as my, pardon the expression, "header" for my blog.) I've been planning a possible trip to the desert this summer. Wonder if I can convince him to come along...