I saw him onstage in NYC when he was doing 'The Iceman Cometh' - I had an orchestra seat and from where I was sitting, it was clear that he was freeballing. There were numerous reports that he never went onstage wearing underwear, and it was pretty plain to see. There was a really substantial bulge flopping around down there. You could even see the head from time to time. It was pretty sexy...as Mr. Spacey undoubtedly is (I am a big fan, as noted by my name on LPSG, of course!).
I have attached a pic from a performance, as well as another bulge pic. Judge for yourself. HOT.