We are runners. Mostly trail runners and we have had a running joke that when we see muddy socks/shoe or other images - could be beautiful mountains or trails - that is running porn. We want to create hat/t-shirts/socks that simply say RUNPORN or #RUNPORN. There could be a logo or simply a cool way of displaying the words. Maybe a pair of running shoes or trail/mountains as a Silhouette in the background.