I enjoy exposing my full twitching erection to guys in vans looking for something to see, seeing it moving around by itself, but then I have to explicitly stroke it with my hand up ad down and also some hip thrusting/humping. At some red lights they've seen me erupting like a volcano. I'm 7" fully erect, 5.25 in girth at the base using the cloth measuring tape. The girth/thickness greatly adds to my intense pleasure.