100% straight, but I enjoy talking about size and experiences with it. It's just this big mystery that nobody is generally allowed to discuss, because it grosses people out, gives the illusion of disloyalty in a monogamous relationship, implies insecurity, etc etc etc. There's not really an outlet for talking about being massively hung, other than a site like this.
And just saying, if I were a huge Star Wars fan and I could use the Force, I'd want to be able to tell people and share it. Having a huge dick is kind of like that, but you aren't allowed to tell anyone that you're living your dream.