I've commented here about these sort of teasing shots before. Just give us the whole monty, Tom. Let is see you in all your glory. When you're half-hard like this but still slightly covered, it's not somehow more "appropriate."
A fully naked shot could not be considered any more "porn" than these are -- if anything, I could make the argument the other way. After all, Rodin never showed tumescence, Tom, nor any hint a fluffer might be somewhere nearby in the studio. Unlike these.
Now if you whipped out your dick, stroked it until it was rigid, then shot a big creamy load all over the photographer's seamless, then that might be outright porn. I certainly wouldn't complain about such a shot, however.