Stroking my hard cock in public

Sometimes when running errands on a weekend I will wear lose fitting cotton gym shorts commando style, which turns me on because I can feel the head of my cock rubbing against the fabric. So while driving from place to place if I see a hot female I can reach inside the shorts and pull my hard member out and stroke it, "without anyone seeing what I am doing" But many times the outline / bulge of my cock is plain to see when I am walking, so as soon as I get in the store I grab a shopping cart for some sense of hiding it. I have had several females notice it then look at me and then another long hard look at my bulge with admiration not disgust.